A German army convoy consisting of 130 soldiers and 60 military vehicles arrived in Lithuania on Friday to strengthen the NATO Enhanced Forward Presence battlegroup led by Germany in the light of growing threats of a Russian invasion of Ukraine.

Russia's armed forces are ready to launch a large military assault on Ukraine "at any time," Lithuania's top military officer warned Friday, echoing concerns from other Western nations.

In a phone discussion Thursday, U.S. President Joe Biden and German Chancellor Olaf Scholz reviewed Russia's military buildup in Ukraine and emphasized the significance of strengthening NATO's eastern flank in the event of an invasion, the White House said.

Biden stated Thursday that Russia now had every reason to attack Ukraine, including indications that it was launching a false flag operation to create a pretext, following an exchange of fire between Ukrainian government forces and pro-Moscow separatists.

World powers are embroiled in one of the most severe crises in East-West relations in decades, jostling for post-Cold War dominance and energy supplies, while Russia seeks to prevent Ukraine from joining NATO.

Russia's defense ministry announced Thursday that it was withdrawing forces following military drills near Ukraine, but the U.S. and NATO claimed Moscow was strengthening its military posture near the border -- not removing troops.

On Tuesday, the convoy of artillery and reconnaissance units departed from Jaegerbrueck in eastern Germany and crossed into Poland overland.

It will be followed in the next two to three days by howitzers mounted on big transport vehicles.

The allied military presence in Lithuania is a "vital deterrent force (against Russia)," Lithuanian Deputy Defense Minister Margiris Abukevicius stated on Thursday.

German government speaker Steffen Hebestreit said "extreme vigilance" is required because no significant evacuation of Russian troops has occurred thus far.

The leaders expressed their appreciation for Putin's remark that diplomatic efforts should continue, he added.

Russian forces are positioned to attack from the north, the east, and Crimea to the south, Rusys said, adding that a simultaneous attack from all three directions is possible.

In 2014, Moscow annexed Crimea from Ukraine.

According to the head of Estonia's Foreign Intelligence Service, Russia is likely to launch a "limited" military operation against Ukraine on Wednesday. Moscow's success there would incentivize it to step up pressure on the Baltic states, he said.

Ukraine is not a NATO member, unlike the three Baltic countries of Estonia, Lithuania, and Latvia.

Russia wants NATO to commit to never admitting Ukraine, something the organization has ruled out.