Threat of Russia invading Ukraine 'very high': Biden

United States President Joe Biden on Thursday said that the threat of Russian invasion is 'very high' as they have not moved any of their troops out.

"The threat is very high-- because they have not moved any of their troops out," Biden said, adding that 'we have reason to believe they're engaged in a false flag operation to have an excuse to go in'.

"Every indication we have is they're prepared to go into Ukraine, attack Ukraine -- number one," Biden said.

"Number two, I've been waiting for a response from Putin for my letter that -- my response to him. It's come to that Moscow embassy. They're faxing it here. Not faxing it, they're sending it here. I have not read it yet. I cannot comment on it," Biden added.

The US President said there is still 'a diplomatic path'.

However, responding to a query whether he will call Putin, Biden said, "I've no plans to call Putin."