World leaders are warning that Russia’s long-simmering threat to invade Ukraine can escalate at any moment.

President Joe Biden, in a Thursday interview with NBC News, said “things could go crazy, quickly,” and urged Americans in Ukraine to leave immediately.

U.S. Secretary of State Antony Blinken echoed that sentiment on Friday, saying that “troubling signs of Russian escalation” indicate that “we’re in a window when an invasion could begin at any time, and to be clear, that includes during the Olympics.”

That timeframe matches a new CNN report:

The US and its allies have new intelligence that suggests Russia could launch an attack on Ukraine even before the end of the Olympics, multiple sources familiar with the matter tell CNN. 

Previous assessments had suggested that Russia was unlikely to move into Ukraine until after the Olympics end on Feb. 20, US officials had told CNN in the past. The revelation of the new intelligence comes as administration officials have dramatically ramped up the urgency of their public warnings related to Ukraine in the past 24 hours.

Biden gathered his top national security advisors in the White House Situation Room on Thursday evening to discuss the looming threat.

On Friday morning, the president convened a virtual meeting with European allies and NATO officials. In Moscow, U.K. Defense Secretary Ben Wallace met with Russia’s Defense Minister Sergei Shoigu.

“I was clear about the tragic consequences that any invasion of Ukraine could have for all people, both Ukrainian, Russia, and the security of Europe,” Wallace told reporters, adding that he had received assurances that Russia had no intention of invading its neighbor.

CBS News reports:

The flurry of diplomatic activity comes as Russia has deployed six warships to the Black Sea, restricting, if not completely cutting off Ukraine’s naval access and increasing the number of Russian forces now encompassing the former Soviet republic.  

Russia, weary of its shrinking geopolitical influence, wants Western nations to guarantee that Ukraine won’t be admitted into NATO. But world leaders aren’t willing to let Russia dictate its alliances.

“NATO will not compromise on core principles,” NATO Secretary General Jens Stoltenberg said at a news conference Thursday. “Renewed Russian aggression will lead to more NATO presence, not less.”

The United States has increased their military presence in Eastern Europe and has supplied antitank weapons to Ukraine in order to bolster their defenses against Russia. Other nations have offered similar assistance.