The Pentagon says more and more Russian troops are amassing near Ukraine, and it is not convinced this is just a training exercise

• The Pentagon says that the Russian military buildup near Ukraine is larger than the one in 2014.
• The Defense Department also said that it is not clear "that this is all about training," as Russia says.
• The US has also raised concerns about Russian plans to block parts of the Black Sea.

The buildup of Russian armed forces along the Ukrainian border has continued, and there are now more Russian troops in the area than there were at the time of the 2014 invasion of Crimea, the Department of Defense said Monday.

"It is certainly bigger than that one in 2014," chief Pentagon spokesperson John Kirby said. "We do continue to see that buildup," he said, characterizing the situation as "seriously concerning."

The Pentagon has declined to provide specific intelligence on how many Russian troops have taken up positions near Ukraine. A senior European Union official, however, estimated the size of the Russian force to be around 100,000 troops.

The senior official, High Representative of the EU Josep Borrell, said Monday that the deployment is the largest-ever military buildup of Russian troops on Ukraine's borders and asserted that there is a risk of further escalation.

Without offering specifics, a US official anonymously told Reuters that there were tens of thousands of Russian troops amassed near Ukraine. Another US official told The Wall Street Journal there are at least 80,000 troops in the area.

Russia has argued that its military activities in the west are "training exercises" in response to "threatening" actions by NATO. The Pentagon is not buying that explanation.

"We certainly heard the Russians proclaim that this is all about training. It's not completely clear to us that's exactly the purpose," Kirby said Monday. "We remain seriously concerned about this build up, and we call on Russia to be more transparent about their intentions."

"In a few weeks from now they will be close to sufficient combat readiness to pursue a military escalation. By our estimations, their combined military force will reach over 120,000 troops by then," Ukrainian Foreign Minister Dmytro Kuleba told The Journal. "We don't know whether Putin will decide to attack, but he will certainly be ready to do so."

Air Force Gen. Tod Wolters, head of US European Command and NATO's supreme allied commander for Europe, said last week that his assessment of the risk of a Russian invasion was "low to medium," saying he expects the risk to wane over the next couple of weeks. EUCOM did, however, raise the threat level in response to Russian activities.

Significant increases in the number of Russian troops positioned near Ukraine come as Russia moves forward with plans to block the movements of foreign ships in parts of the Black Sea, where the Russian military has gathered a number of warships and aircraft for reported exercises.

State Department spokesman Ned Price said Monday that the US is deeply concerned by these plans.

"Russia ahs a history of taking aggressive actions against Ukrainian vessels and impeding access to Ukraine's ports in the Sea of Azoz, impacting Ukraine's international commerce," he said. "This represents yet another unprovoked escalation in Moscow's ongoing campaign to undermine and destabilize Ukraine."

The Biden administration has stressed that it supports Ukraine's sovereignty and territorial integrity. President Joe Biden personally raised the issue of Russia's military buildup near Ukraine on a phone call with Russian President Vladimir Putin last week, urging Russia to "deescalate tensions."

Prior to that presidential call, Secretary of State Antony Blinken said "if Russia acts recklessly, or aggressively, there will be costs, there will be consequences."