Biden's top diplomat says the Winter Olympics won't stop Russia from invading Ukraine

• Russia could invade Ukraine during the Olympics, Blinken warned on Friday.
• "We're in a window when an invasion could begin at any time," Blinken said.

Secretary of State Antony Blinken on Friday warned that the Winter Olympics in Beijing will not deter Russia from invading Ukraine.

"Simply put, we continue to see very troubling signs of Russian escalation, including new forces arriving at the Ukrainian border," Blinken said during a press conference in Melbourne, Australia, per the Associated Press.

"We're in a window when an invasion could begin at any time and, to be clear, that includes during the Olympics," Blinken added, while reiterating the administration's call for Americans in Ukraine to leave.

In 2014, Russia invaded Ukraine and annexed Crimea on February 20 — three days before the Winter Olympics in Sochi ended that same year. And Russia in 2008 invaded Georgia on August 1, which was about a week before the Summer Olympics began in Beijing that year.

This year's Games in Beijing end on February 20.

In late January, Deputy Secretary of State Wendy Sherman suggested Russian Vladimir Putin would avoid invading Ukraine while the Winter Olympics were ongoing in Beijing. China and Russia often side with one another on geopolitical issues.

"We all are aware that the Beijing Olympics are beginning on February 4th, the opening ceremony, and President Putin expects to be there. I think that probably President Xi Jinping would not be ecstatic if Putin chose that moment to invade Ukraine," Sherman said to a virtual chat hosted by the Yalta European Strategy. "So that may affect his timing and his thinking."

But the Biden administration's assessment has seemingly changed.

President Joe Biden in recent days has repeatedly urged any Americans in Ukraine who are not part of the diplomatic corps to leave as soon as possible.

"American citizens should leave now," Biden said Thursday in an interview with NBC News anchor Lester Holt. "It's not like we're dealing with a terrorist organization. We're dealing with one of the largest armies in the world. It's a very different situation, and things could go crazy quickly."

Russia has gathered roughly 130,000 troops on Ukraine's border. The Kremlin claims it doesn't plan to invade, but has refused to pull its troops back to help reduce tensions.

Diplomatic efforts by the US and its allies to prevent a broader conflict have yet to produce any major breakthroughs. Moscow has made demands for binding security guarantees from the West, including banning Ukraine and Georgia from ever joining NATO. The alliance and Washington have consistently emphasized that no concessions will be made on this demand.

The US will not send in troops to defend Ukraine, because it's not a NATO member, if Russia invades. But several thousand US troops have been deployed to NATO member countries in the region as a sign of Washington's support for the alliance amid the tensions with Russia.