President Joe Biden has accepted "in principle" a meeting with President Vladimir Putin provided Russia does not invade Ukraine, the White House has said, in a last-ditch diplomatic overture brokered by French President Emmanuel Macron to ease one of the worst security crises in Europe in decades.
The US has repeatedly warned of Russia's plans to invade Ukraine and threatened to impose tough sanctions on Moscow if it goes ahead with its plans. However, Russia has denied that it plans to attack Ukraine.
"As the President has repeatedly made clear, we are committed to pursuing diplomacy until the moment an invasion begins," White House Press Secretary Jen Psaki said in a statement on Sunday.
Psaki said that US Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov are scheduled to meet later this week in Europe, provided Russia does not proceed with military action.
President Biden accepted in principle a meeting with President Putin following that engagement, again, if an invasion hasn't happened. We are always ready for diplomacy, she said.
Psaki said that Biden spoke with Macron on Sunday and the two leaders discussed ongoing diplomacy and deterrence efforts in response to Russia's military buildup on the borders of Ukraine.
According to US estimates, Russia has amassed over 150,000 in and near Ukraine, up from about 100,000 on January 30.
We are also ready to impose swift and severe consequences should Russia instead choose war. And currently, Russia appears to be continuing preparations for a full-scale assault on Ukraine very soon, she said.
The development comes after Blinken in an interview to CNN said that Biden is prepared to engage with Putin in any format, at any place and time to prevent a war.
Blinken asserted that everything leading up to the actual invasion of Ukraine appears to be taking place.
"As we have described it, everything leading up to the actual invasion appears to be taking place, all of these false flag operations, all of these provocations to create justifications. All of that is already in train," Blinken told CNN.
"We believe President Putin has made the decision, but until the tanks are actually rolling and the planes are flying, we will use every opportunity and every minute we have to see if diplomacy can still dissuade President Putin from carrying this forward, he said.
"President Biden is prepared to engage President Putin at any time, in any format, if that can help prevent a war. I reached out to my Russian counterpart, Foreign Minister (Sergey) Lavrov, to urge that we meet next week in Europe. The plan is still to do that, unless Russia invades in the meantime, Blinken said in response to a question.
President Biden said on Friday that based on the latest American intelligence, he was "convinced" that Putin has decided to invade Ukraine in the coming days.
Putin has been demanding assurances that NATO will not admit Ukraine, a former Soviet state with close ties to Russia, while the Western alliance denies it poses any threat to Russia.
There are fears that a Russian military intervention could start a war even bloodier than the conflict in eastern Ukraine which has cost at least 14,000 lives.
Blinken has alleged that Russia is trying to create a series of provocations as justifications for aggression against Ukraine going forward.
Meanwhile, they have been escalating the forces they have across Ukraine's borders over the last months from 50,000 forces to 100,000 to now more than 150,000, he said.
"So, all of this, along with the false flag operations we have seen unfold over the weekend, tells us that the playbook that we laid out is moving forward, he said.
Blinken said that the US, with its European partners and allies, have prepared a massive package of sanctions against Russia in case of an invasion of Ukraine.
The G7 countries in Munich came together, reiterated that there would be massive consequences for Russia if it pursues this aggression, he said.
"The purpose of the sanctions in the first instance is to try to deter Russia from going to war. As soon as you trigger them, that deterrent is gone. And until the last minute, as long as we can try to bring a deterrent effect to this, we're going to try to do that, he said.
Meanwhile, US Defence Secretary Lloyd Austin on Sunday categorically ruled out deployment of American troops in Ukraine and warned Moscow of punitive sanctions if its troops crossed over the border.
"President Biden has been very clear about the fact that we're not going to employ forces in Ukraine. And we will make sure that we do everything possible to protect our troops and our Polish partners so that there isn't a spillover cross-boundary, Austin told ABC News in a separate interview.
Referring to the nature of deployment of Russian troops on the border of Ukraine, he said there is a significant amount of combat power moving very quickly now to take Kyiv.
"We see a lot of tanks and armoured vehicles there. We see a lot of artillery. We see rocket forces. If he employs that kind of combat power, it will certainly create enormous casualties within the civilian population and so this could create a - tragedy, quite frankly, in terms of refugee flow and displaced people. So this is potentially a very, very dangerous (situation)," he added.
On Friday, Russia announced nuclear drills, even as leaders of nations from the West looked for ways to ease the tensions.
UN Secretary General Antonio Guterres on Friday warned that it would be catastrophic if the Russia-Ukraine conflict escalated into a war, while underlining that there was no alternative to diplomacy.