While Russian President Vladimir Putin's plan to station nuclear weapons in neighboring Belarus is unlikely to change Europe's strategic balance, it has put him at odds with a pledge he made with Chinese counterpart Xi Jinping just days earlier.

Russia and China declared that "all nuclear weapons states should refrain from deploying nuclear weapons abroad" in a joint statement at the end of Xi's visit to Moscow last week. Then Putin announced on state television late Saturday that Russia will place tactical nuclear weapons in Belarus for the first time since the Soviet Union's collapse, even as he insisted the move wouldn't breach Moscow's nonproliferation commitments.

"Putin's statement cast doubt on the outcome of his meeting with Xi," said Tariq Rauf, the International Atomic Energy Agency's former nuclear nonproliferation director. "He seems to be nuclear signaling to a domestic audience, trying to reassure his own public that Russia is doing OK, that the war in Ukraine is going all right."

Nonproliferation analysts say there aren't any technical barriers preventing Russia from deploying weapons to secure Belarusian bunkers by July. Putin said storage facilities would be ready by July 1, without indicating when Russia would send nuclear arms to its ally's territory.

His attempt to escalate confrontation with the U.S. and NATO over Russia's war in Ukraine received a cool response in Washington and among Kyiv's allies in eastern European states that border Belarus. Officials in Poland and the Baltic States criticized Moscow's latest nuclear saber-rattling, while insisting the deployment, if it happens, would be of largely symbolic significance in security terms.

"The reaction should be calm and firm," Poland's European Union Affairs Minister Szymon Szynkowski vel Sek told reporters in Poznan on Monday. "We cannot let them frighten us. We should continue our efforts to support Ukraine without letting emotions get in the way."

Russian nuclear weapons are already stationed in Kaliningrad, its exclave wedged between Poland and Lithuania, and are geographically closer to military targets in the Baltic Sea and western Europe than they would be if stationed in Belarus.

With Russian troops bogged down in eastern Ukraine, Xi's three-day visit to Moscow was by far the most significant since Putin began the invasion more than 13 months ago, and it produced a flurry of economic and nuclear agreements. Putin's intention to return nuclear weapons to Belarus suggests Beijing and Moscow may interpret their commitments differently, with former U.S. ambassador Michael McFaul saying it showed a lack of respect toward Xi.

"Under the current circumstances, all sides need to focus on making diplomatic efforts toward a peaceful settlement of the Ukraine crisis and work together for de-escalation," China's Foreign Ministry spokeswoman Mao Ning said Monday, adding that a nuclear war should never be fought and can never be won.

Ten aircraft adapted to carry nuclear weapons have been prepared in Belarus, Putin said. Russian Iskander short-range missiles - capable of carrying nuclear warheads — have also been sent to Belarus, and training for crews would begin there on April 3, he told state TV.

As part of the Soviet Union, Belarus stored scores of mobile warheads and tactical nuclear weapons at various bases during the Cold War. Technical barriers to rejuvenating that infrastructure are low, according to Robert Kelley, a former U.S. nuclear-weapons engineer and intelligence analyst.

"It's really just about security and if you're heavy on guns and guards it won't be much of an issue," he said, adding that the decision to deploy in Belarus is a political one that isn't linked operationally to the war in Ukraine. The Belarusian military airfield of Baranavichy has facilities that can probably be quickly converted to host weapons, he said.

Belarusian President Alexander Lukashenko allowed Putin to use his country's territory to launch Russia's invasion of Ukraine in February last year and has consistently supported the Kremlin leader's actions, while holding back from allowing his own military to take part in the war.

Putin defended his decision to move nuclear weapons to Belarus by saying the U.S. had long stationed them in North Atlantic Treaty Organization countries. Germany and the Netherlands are among U.S. allies that host nuclear weapons. Finland may also revisit its nuclear policy once completing its membership in NATO.

"Russia is showing weakness, not strength," Lithuanian Foreign Minister Gabrielius Landsbergis said on Twitter. "Serious sanctions, troop deployments in the Baltics and more air+sea defense systems on the eastern flank of NATO would send a message of solidarity and determination, not fear and prevarication."

Bloomberg's Natalia Ojewska and Aaron Eglitis contributed to this report.