British Prime Minister Boris Johnson will vow to uphold Ukraine's sovereignty on a visit to Kyiv as part of the West's diplomatic efforts to stop a possible Russian invasion which Moscow says there is no proof it is planning.
Tensions were on display at the United Nations Security Council, meanwhile, over the troop build-up near Ukraine as both Russia and the United States used the international forum to label each other as "provocative".
Mr Johnson, who is facing calls to quit over gatherings held at his offices despite lockdown rules, is due to meet Ukraine's President Volodymyr Zelenskyy as he focuses on Britain's global role in the world, which he has touted often since Brexit.
The visit comes as the US said it is in active discussions with allies about possible US troop deployments to NATO's eastern flank, separate from some 8,500 forces already placed on alert last week.
"We urge Russia to step back and engage in dialogue to find a diplomatic resolution and avoid further bloodshed," Mr Johnson said in remarks released ahead of his arrival.
Mr Johnson is due to discuss with Zelenskyy what strategic support Britain can offer to Ukraine.
London has supplied defensive weapons and training personnel to Ukraine, though ministers have said that the deployment of combat troops is unlikely.
Russia accuses US of trying to 'whip up hysterics'
The United States and its allies have prepared a list of Russian elites — in or near President Vladimir Putin's inner circle — to punish with sanctions if Russia sends troops into Ukraine, a senior US official said in the wake of the UN Security Council meeting.
At the meeting, requested by Washington, Moscow lost an attempt to block a public meeting discussing its troop build-up near Ukraine's borders and Western fears of an invasion.
US ambassador Linda Thomas-Greenfield dismissed a charge by Russian ambassador Vassily Nebenzia that Washington was trying "to whip up hysterics" and use "megaphone diplomacy" by calling the first Security Council meeting on the crisis.
She added that, although the US was seeking a peaceful resolution without confrontation, "we will be decisive, swift and united should Russia further invade Ukraine".
The vote on holding an open meeting passed 10-2, with Russia and China opposed, and three abstentions. It only needed nine votes to be approved.
UN under-secretary-general for political affairs Rosemary DiCarlo then went ahead with an open briefing that was followed by speeches from the 15 council members.
Mr Nebenzia said the West's assertion that Russia had amassed 100,000 troops near Ukraine had not been confirmed by the international body and there was no proof it was planning military action.
Mr Nebenzia said US talk of war was "provocative", that Russia frequently deployed troops in its own territory, and that Ukraine's crisis was a domestic issue.
After the meeting, US President Joe Biden said in a statement the gathering was "a critical step in rallying the world to speak out in one voice", to reject the use of force, seek military de-escalation, support diplomacy and demand accountability from every member "to refrain from military aggression against its neighbours".
Both Washington and London declined to name who they planned to target with the proposed sanctions.
"The individuals we have identified are in or near the inner circles of the Kremlin and play a role in government decision-making or are, at a minimum, complicit in the Kremlin's destabilising behaviour," a US official in Washington said.
"Putin's cronies will no longer be able to use their spouses or other family members as proxies to evade sanctions.
"Sanctions would cut them off from the international financial system and ensure that they and their family members will no longer able to enjoy the perks of parking their money in the West and attending elite Western universities."
Britain again urged Putin to "step back from the brink" after the Russian build-up of troops near Ukraine stoked fears of war, and warned any incursion would trigger sanctions against companies and people close to the Kremlin.
Foreign Secretary Liz Truss said planned legislation would give London new powers to target companies linked to the Russian state, as well as to freeze individuals' assets and deny them entry to Britain.
Kremlin spokesperson Dmitry Peskov called the British warning "very disturbing", saying it made Britain less attractive to investors and would hurt British companies.
"It's not often you see or hear such direct threats to attack business," he said.
"An attack by a given country on Russian business implies retaliatory measures, and these measures will be formulated based on our interests if necessary."
US, UK plan more Russia talks this week
The session kicked off more high-level diplomacy this week, although talks between the US and Russia have so far failed to ease tensions in the crisis.
Russia has massed the estimated 100,000 troops near the borders of its southern neighbour, stoking fears in the West of an invasion.
However, Russia denies it intends to launch an attack, demanding that NATO promise never to allow Ukraine to join the alliance, halt the deployment of NATO weapons near Russian borders, and roll back its forces from Eastern Europe.
Both NATO and the US have called those demands impossible.
Russian Foreign Minister Sergey Lavrov and US Secretary of State Antony Blinken didn't make any visible progress in easing the tensions at their meeting in Geneva last month.
They are expected to speak by phone on Tuesday, according to the Russian Foreign Ministry.
Mr Biden warned Ukrainian President Volodymyr Zelenskyy in a phone call last week that there was a "distinct possibility" Russia could begin an incursion in February, but the Ukrainian leader sought to play down the war fears, saying Western alarm over an imminent invasion has prompted many investors in the country's financial markets to cash out.
On Friday, Mr Zelenskyy said that "we aren't seeing any escalation bigger than before", and charged that the Russian build-up could be an attempt by Moscow to exert "psychological pressure" and sow panic.
Both the United States and Britain are trying to signal to Mr Putin that Russia's richest men, who have huge assets abroad, will face punishment if he orders troops to invade Ukraine.
US accused of causing 'hysteria'
Kremlin spokesman Dmitry Peskov said that "hysteria promoted by Washington triggers hysteria in Ukraine, where people are almost starting to pack their bags for the front line".
Any formal action by the Security Council is extremely unlikely, given Russia's veto power and its ties with others on the council, including China.
Speaking on the US ABC News program This Week, Ms Thomas-Greenfield said of Russia: "We're going into the room prepared to listen to them, but we're not going to be distracted by their propaganda."
Last week she said that council members "must squarely examine the facts and consider what is at stake for Ukraine, for Russia, for Europe, and for the core obligations and principles of the international order should Russia further invade Ukraine".
On Friday, China's UN Ambassador Zhang Jun said both sides have shown willingness to continue negotiations and should be allowed to continue.
Mr Zhang said that Russia had said it had "no intention to have a war" and that the Security Council should "help to de-escalate the situation instead of adding fuel to the fire".
On Sunday, the chairman of the Senate Foreign Relations Committee, Senator Bob Menendez, said that, in the event of an attack, politicians want Russia to face "the mother of all sanctions".
That includes actions against Russian banks that could severely undermine the Russian economy as well as increasing lethal aid to Ukraine's military.
The sanctions under consideration would apparently be significantly stronger than those imposed after Russia annexed Crimea from Ukraine in 2014.
Those penalties have been seen as ineffective.
Mr Menendez also raised the prospect of imposing some punishments pre-emptively, before any invasion.
ABC/wires
