Russia is continuing to build up forces close to Ukraine even as it prepares for security talks with the U.S., keeping up pressure with a deployment that could turn into a rapid invasion or a long-term threat.

Citing “further troop movements on the border,” German Foreign Minister Annalena Baerbock told reporters “my concern is great” and called for dialogue Wednesday. Russia now has 122,000 troops within 200 kilometers (120 miles) of the border, according to Ukraine’s Security and Defense Council.

Satellite images show tanks, artillery and air-defense systems have been moved to border regions near Ukraine since November, according to defense-intelligence firm Janes. While the images appear to show limited troop numbers on the ground with the equipment, Russia would be able to reinforce them quickly and covertly with large deployments using trains or aircraft, it said.

The U.S. and its European allies have warned Russia of massive consequences if it attacks neighboring Ukraine as they struggle to decipher President Vladimir Putin’s intentions. The Kremlin denies it plans to invade.

The massing of forces “is a classic demonstration of strength that’s necessary to dishearten your opponent as much as possible,” said Natalya Kharitonova, an international security expert at the Russian Presidential Academy of National Economy and Public Administration. “This does not indicate an iron determination to use it.”

The Kremlin already got some of what it wanted when the U.S. agreed to hold talks on Russia’s demand for “legally binding” security guarantees that would prevent the North Atlantic Treaty Organization from expanding further east, barring Ukraine from its goal of eventually gaining membership.

The U.S. says it’s ready to hold talks in January on two draft security treaties Russia published last week, though it’s called some proposals “unacceptable.” American intelligence shared with European allies last month showed Russia may be planning an invasion of Ukraine as soon as next month involving as many as 175,000 troops.

The Kremlin says Russia is entitled to deploy troops wherever it likes on its own territory.

Ukraine Thursday said it had “moderate optimism” for a de-escalation in the eastern Donbas region after agreeing on the need to resume a ceasefire. Russian-backed rebels have been fighting Ukrainian troops there since 2014 in a conflict that’s killed more than 14,000 people. Meanwhile, the Russian Defense Ministry announced military exercises involving 1200 marines in the Crimea peninsula that Russia annexed in 2014 from Ukraine and the southern Krasnodar region, Interfax reported.

Part of the existing force built up near the border was left over from April, when Russia carried out a similar military buildup near Ukraine before tensions eased after U.S. President Joe Biden offered Putin a summit meeting in phone talks.

Russian General Staff Chief Valery Gerasimov and U.S. Joint Chiefs of Staff Chairman Mark Milley discussed international security issues in a phone call Wednesday, the Interfax news service reported, citing the Defense Ministry in Moscow.

“If Russia decides to invade, they can do so on relatively short notice,” said Rob Lee, a fellow at the U.S-based Foreign Policy Research Institute. “Once the equipment is there, the heavy stuff has already been moved and you can very quickly dispatch troops to man it,” he said.

Russia will “do everything” to make the West understand its position, Foreign Minister Sergei Lavrov said Wednesday in an interview with RT TV. “I hope that, taking into account the actions we are taking to ensure our defensive capability, we will be taken seriously.”