As Russia masses tens of thousands of troops on its border with Ukraine, along with tanks, artillery and missiles capable of striking the capital, officials in Washington, Kyiv and across Europe are debating the likelihood and timing of an invasion.

In one camp, officials in Washington, London and within Ukraine’s national security establishment are convinced that a Russian strike is imminent. But Ukraine’s president, Volodymyr Zelensky, is not persuaded that the intelligence Western nations have shown him backs up their dire assessments.

Somewhere in the middle, U.S. allies including France, Germany and Norway think Russia could strike but remain unsure of the timing and whether Russian President Vladimir Putin will accept some kind of diplomatic compromise that he can sell as a NATO retreat.

Intelligence is rarely predictive, and judging the precise moment when Putin might order his forces over the border is difficult and perhaps impossible, U.S. officials acknowledged. But in recent weeks, they and their allies, including those in Kyiv who do not share Zelensky’s sanguine view, have sounded exasperated with the Ukrainian president and his closest political advisers, some of whom have asserted that the White House is hyping the threat of an invasion for ulterior motives.

“There is a growing sentiment that the United States is exaggerating the threat for political reasons,” one Zelensky aide said, perhaps to force Ukraine to accept Russia’s demand that it be barred from joining NATO.

Biden officials have flatly rejected the accusation and stressed that they are providing Ukraine with detailed information about a potentially existential threat. On Friday, as it has day after day, the administration continued to strike an ominous tone.

“The threat is very real and it’s imminent,” John Sullivan, the U.S. ambassador to Russia, told journalists. “As President Biden has said, it could happen, given the buildup that we have seen, with very little notice.”

Some officials said Putin might order an attack after the Feb. 20 conclusion of the Olympic Games in Beijing, timing the event so as not to upstage China, an important ally.

At a news conference Friday, Zelensky effectively shrugged. Putin, he said, may have sent upward of 100,000 troops to Ukraine’s border as an act of “psychological pressure.” Regarding intelligence including satellite imagery and other information that shows Russia could deploy up to 175,000 troops, Zelensky said, “If you look only at the satellites, you will see the increase of troops. You can’t assess whether this is a threat, attack or simple rotation.”

Zelensky and his team haven’t ruled out that Russia might invade, and by many outward appearances, Ukraine is preparing for war. The country is receiving shipments of arms and military assistance from allies. Volunteers are training to fight in the streets of Kyiv. Ukrainian intelligence has moved sensitive files and equipment out of its headquarters in the capital to safe locations in the west of the country, according to officials familiar with the matter who, like others spoke on the condition of anonymity to discuss sensitive operations.

But Western officials have been unsettled by Zelensky and his team’s public skepticism and what they perceive as his lack of focus.

“There’s this split among his administrative advisers and what he may be hearing from his military and intelligence services,” said a U.S. government official specializing in Russian affairs. “I think Zelensky and his political team are working from their own set of priorities, and they do not necessarily accord with those of the intelligence and military.”

Instead of devoting his full attention to steeling Ukrainian society for a fight, one senior European diplomat said, Zelensky has presided over treason charges against his predecessor, candy baron Petro Poroshenko, who this month flew to Ukraine to defend himself in court. Each man accuses the other of a pursuing a political vendetta.

The fight has further fractured Ukrainian political life at a time when unity is badly needed, the diplomat said, raising questions among NATO allies about how much backing Zelensky would command in Ukraine if a war broke out.

The tone from Zelensky and his team is starting to change, the diplomat said, to one of greater concern. But there is lingering uncertainty about whether the Ukrainians are calibrating their response to reflect what they believe the leaders of NATO nations want to hear.

Yuri Vitrenko, the chief executive of Naftogaz, the largest national oil and gas company in Ukraine, said Zelensky’s outlook that a Russian invasion is not imminent reflects briefings from his top advisers.

“Zelensky’s view is based on the intelligence data we have,” said Vitrenko, who speaks frequently with the president and his top aides

There are two necessary ingredients for an imminent invasion, he said: a buildup of troops and a political pretext. “Russia still needs a pretext.”

When Russia invaded Georgia in 2008, it cited the movement of Georgian security forces into the separatist enclave of South Ossetia as a rationale for military action. In 2014, it exploited pro-Russian demonstrations and sent in troops without insignia to take control of Crimea. Vitrenko said Russia’s core demand - that Ukraine be barred from NATO - is a beef with the West, not a cause for an assault on Kyiv.

There is uncertainty also in other parts of Europe.

French officials agree with their U.S. counterparts on the danger and scale of the threat from Russia, but there are differences concerning predictions about how imminent a Russian invasion may be, said a French official.

“The appreciation of the threat and the risk is completely shared. The fact that there is huge volatility and risk of miscalculation is completely shared as well, and we are very wary of that,” said the French official, who said his government is, however, less certain that an attack will happen soon.

For its part, Germany also remains skeptical of an imminent Russian invasion. At this stage, Berlin sees no indication that Russia will move into Ukraine immediately, a senior German official said. Evidence that Moscow plans to act quickly may exist, but if the United States possesses it, it hasn’t shared it with the Germans, the official added.

The official stressed that the Russian military buildup was “very alarming,” but without clear indications of what Putin plans to do next, Germany does not want to take any provocative actions. Germany has refused to join other NATO members in sending arms to Ukraine but has emphasized its efforts to stabilize the country’s economy as one of its biggest donors.

Chancellor Olaf Scholz has said Germany will stand with its allies should Russia invade.

“There would be a high price” for Russia, Scholz told reporters.

Norwegian Prime Minister Jonas Gahr Store said that creating uncertainly is a Putin trademark. “The fact that you get different readings of will there be an invasion or not is exactly what the Russian president wants to happen,” he said in an interview. “He wants there to be ambiguity.”

Zelensky advisers say the Ukrainian president is also mindful of not inciting a public panic. Were he to echo the bleak White House assessment, they worry he could set off a bank run and capital flight. One aide complained that U.S. financial assistance is being offset by the damage that talk of war is doing to Ukraine’s economy.

Public panic also could lead to social unrest, Zelensky advisers fear, and destabilize his administration, perhaps paving the way for Moscow to install leaders more favorable to the Kremlin. Indeed, U.S. and British officials feared Putin was trying such a scheme. Last week, British Foreign Secretary Liz Truss publicly accused Russia of organizing a plot to install a pro-Moscow government led by a former member of Ukraine’s parliament.

The intelligence underlying that revelation, which also linked some former Ukrainian politicians to Russian intelligence officers involved in planning for an attack on Ukraine, was collected and declassified by the United States, according to multiple people familiar with the matter. The Biden administration asked the British government, which vetted the intelligence and was confident in its accuracy, to publicly expose the Russian plotting, the people said.

U.S. intelligence has assessed that Putin has underestimated how costly an invasion could be in Russian lives lost and in the devastating effects of sanctions on Russia’s economy, according to officials familiar with the information.

Intelligence analysts also have concluded that Putin is being misinformed by his own circle of advisers, who appear unwilling to confront him with the full consequences of military action.

“To me, the idea of invading Ukraine and occupying it in any way, even temporarily, is extraordinarily ambitious and somewhat insane,” said the U.S. official specializing in Russian affairs. “It’s a big country. He may have a plan to defeat the Ukrainian military very quickly. But I think lessons of history should teach him that [success] does not resolve many or even most of the other challenges that he will have taken on.”

- - -

The Washington Post’s Missy Ryan, Paul Sonne, Karoun Demirjian, Karen DeYoung, Dan Lamothe, Michael Birnbaum and Souad Mekhennet in Washington and David L. Stern in Kyiv contributed to this report.