The White House warned on Tuesday that Russia is preparing for an attack on Ukraine that could occur at "any point", and that the US response will be comprehensive.

"No option is off the table," Press Secretary Jen Psaki told reporters, warning of an "extremely dangerous situation."

"We're now at a stage where Russia could at any point launch an attack on Ukraine," Psaki said.

Blinken: Russia rejects new talks

Moscow, on Tuesday, refused to hold new talks on Ukraine unless the West responds to its demands, as US Secretary of State Anthony Blinken prepares to head to Kiev as a sign of support, after the West's allegations of Russia's intentions to "invade Ukraine".

Today, Tuesday, the US Secretary of State, Antony Blinken, in a call with his Russian counterpart, Sergey Lavrov, called for a diplomatic approach to end the crisis in Ukraine, the US State Department confirmed.

Blinken, Russian FM to meet in Geneva Friday on Ukraine

According to a US official, Secretary of State Antony Blinken will visit Russian Foreign Minister Sergey Lavrov in Geneva on Friday in the hopes of achieving a "diplomatic off-ramp" from the Ukraine issue.

"Secretary Blinken is 150 percent committed to seeing if there is a diplomatic off-ramp here and that is the impetus behind this engagement with Foreign Minister Lavrov," the official told reporters on condition of anonymity Tuesday.

"It's really an opportunity for the US to share our major concerns with Russia and to see where there might be an opportunity for Russia and the United States to find common ground," she said.

Blinken will fly to Ukraine later Tuesday in a show of support for the country as tens of thousands of Russian troops swarm on its border.

He'll then travel to Berlin for four-way discussions on the issue with Britain, France, and Germany, as Western nations threaten Russia with dire consequences if it invades Ukraine.

Blinken expressed concern over Russian moves into Belarus

According to the US official, Blinken agreed to the meetings with Lavrov over the phone, but it's possible that Russia isn't interested in a diplomatic solution.

"I think it's still too early to tell if the Russian government is genuinely interested in diplomacy, if it is prepared to negotiate seriously in good faith, or whether it will use discussions as a pretext to claim that diplomacy didn't address Moscow's interests," the official said. The official reiterated that the US is ready to invade if Russia chooses to do so.

Along with economic consequences, "we will provide additional defensive materials to the Ukrainians" if there is an invasion, she said.

The diplomat also expressed concern over Russian moves into Belarus on Tuesday, whose President, Alexander Lukashenko, is a close supporter of Russian President Vladimir Putin.

"The fact that we are seeing this movement into Belarus clearly gives the Russians another approach should they decide to take further military action against Ukraine," the official said.

Belarus, which shares a border with Ukraine, announced that Russian troops had come for military exercises.