A Ukrainian sea border security force soldier mans the machine-gun of a vessel on the Azov Sea on November 28, 2018 in Mariupol, Ukraine. (Martyn Aim/Getty Images)

REAGAN NATIONAL DEFENSE FORUM: The US Army’s top officer said today that he is “very, very concerned” about the Russian military buildup along the Ukrainian border, following reports that the Kremlin is preparing for an invasion of the former Soviet state early next year.

US intelligence has found the Kremlin is planning a multi-front offensive early next year, involving up to 175,000 troops, according to a report Friday by The Washington Post. The report says that the US believes 70,000 Russian soldiers are already near the border, while Ukraine officials estimate the figure to be 94,000.

“That gives a lot of options to the Russians,” said Army Chief of Staff James McConville, speaking at the annual Reagan National Defense Forum. “I’m not quite sure what they’re going to do, but to me, that is a terrible impact on the ability and security of our European friends.”

The Washington Post report says that the potential Russian invasion would be “far larger-scale” than its 2014 invasion and annexation of Crimea. Less than a decade after that successful incursion, Moscow has denied that it plans to invade now, calling the suggestion American “malicious propaganda.”

Asked about US strategy to deter potential Russian hostilities, McConville said that was a question not just for a military officer, but for senior policymakers across the US government in concert with their counterparts the world over.

“The way you deter is you imposed some type of costs to make sure the cost is worth more than the benefit,” McConville said. “That’s a whole-of-government effort, but it’s really a whole-of-Europe effort. It’s really a global effort, making sure people understand you just can’t go in to another sovereign country and conducting malign activities without having some type of cost.”

Even in the context of ongoing conflict in the east, senior Ukrainian government officials have been ringing alarm bells about Russia’s increasing belligerence in recent weeks. Earlier this week, Ukrainian Prime Minister Denys Shmygal told Reuters that the Russian government was behind a coup attempt it uncovered to topple the pro-Western government in Kiev.

Sen. Joni Ernst, who sits on the Armed Services Committee and also spoke at the Reagan forum, called a new Russian invasion of Ukraine a worst case scenario.

“For Ukraine, this would be forever damaging,” Ernst said. “They struggle, of course with their independence and the pressures that are coming from Russia.”

The Iowa Republican blamed the Biden administration, as well as Senate, for being weak on Russia. She pointed to the Senate blocking an amendment to the annual National Defense Authorization Act earlier this week that would’ve place sanctions on Russia for Nord Stream 2, a pipeline from Russia into Europe that critics argue will give Russia vast control over Europe’s energy supply.

As far as deterrence, without being specific, Ernst said that there are a “a number of pre-emptive sanctions” that the US could implement against Russia.

“We need to push back and say, ‘Putin, you can’t do this,'” Ernst said.