Tensions between Russia and the West escalated further on Thursday as the US said the Kremlin may manufacture a "violent event" such as a fake terrorist bombing, a drone strike or even a chemical attack to justify an invasion of Ukraine.
US president Joe Biden said his sense was that Moscow would launch such an invasion within the next several days, and could engage in a "false flag" operation as an excuse to "go in". The Kremlin, in turn, accused Mr Biden of stoking tension.
Russia said the West was ignoring its key security demands and reaffirmed that it could take unspecified “military-technical measures” if the US and its allies continued to stonewall on its concerns.
At the same time, Russia said it was was ready to discuss measures to enhance security in Europe, including limits on missile deployments, restrictions on patrol flights by strategic bombers.
But in a further indication of worsening relations, Russia on Thursday expelled the US deputy chief of mission in Moscow, Bart Gorman. Washington described the move as “unprovoked” and said it would respond.
Amid the diplomatic sparring, Ukraine and Moscow-backed separatists blamed each other for a surge in shelling in the divided east of the country. Russia accused Ukraine of repeatedly violating a 2015 ceasefire aimed at bringing peace to the breakaway Donbas region.
An eight-year war between government troops and Russia’s proxy militia in Donbas has killed 14,000 people.
EU leaders, meanwhile, warned of a "stringent" package of sanctions against Russia in the event of an invasion of Ukraine. Taoiseach Micheál Martin rejected Russian claims that Ukraine and western countries were responsible for provoking tensions.
At the UN Security Council in New York, Irish ambassador Geraldine Byrne Nason said Ireland was a "steadfast and consistent supporter of Ukraine's sovereignty and territorial integrity within its internationally recognised borders".
“Ukraine has the same fundamental right as every other sovereign and independent state to choose its own foreign policy and to ensure the security and defence of its territory,” she said.
US secretary of state Antony Blinken proposed new talks with his Russian counterpart Sergei Lavrov in Europe next week, which he said could "pave the way for a summit of key leaders, in the context of de-escalation, to reach understandings on our mutual security concerns".
Mr Blinken told the Security Council how Washington believed any Russian attack would unfold.
“First, Russia plans to manufacture a pretext for its attack. This could be a violent event that Russia will blame on Ukraine, or an outrageous accusation that Russia will level against the Ukrainian government. We don’t know exactly the form it will take. It could be a fabricated so-called terrorist bombing inside Russia, the invented discovery of the mass grave, a staged drone strike against civilians, or a fake – even a real – attack using chemical weapons.”
Russia’s foreign minister, Sergei Lavrov, said the West was fanning “hysteria” by accusing Moscow of not withdrawing its troops from near the Ukraine border. “This is where the escalation is,” he said.
In a letter delivered to the US ambassador in Moscow on Thursday, Russia said: "In the absence of readiness on the American side to agree on firm, legally binding guarantees on our security from the United States and its allies, Russia will be forced to respond, including through the implementation of military-technical measures."
Russia also urged the West to stop providing weapons to Ukraine and to remove previous supplies.