US President, Joe Biden, has said there is “total unanimity” with European leaders over Russia’s troop build-up on its border with Ukraine.
During crisis talks on Monday, Western powers agreed to “unprecedented” sanctions against Russia if it were to invade.
The US has also put 8,500 troops on alertwhich Russia said caused it “great concern”.
It denies having any plans for an invasion.
However, some 100,000 Russian soldiers have been deployed on Ukraine’s border.
Joining the US and UK in Monday’s talks were the leaders of France, Germany, Italy, Poland and the European Union (EU). The head of North Atlantic Treaty Organisation (NATO), Jens Stoltenberg, also dialed in.
“I had a very, very, very good meeting – total unanimity with all the European leaders,” Mr Biden said afterwards.
A Downing Street spokesperson said the leaders “agreed on the importance of international unity in the face of growing Russian hostility”.
Should a further Russian incursion into Ukraine happen, they agreed that “allies must enact swift retributive responses, including an unprecedented package of sanctions”.
The aim of the 80-minute video call between the allies was to agree on a common strategy against Russia’s actions after some disagreements over how Western nations were responding.
On Monday, UK PM, Boris Johnson, warned that “gloomy” intelligence suggests Russia is planning a lightning raid on the Ukrainian capital, Kyiv, and the UK started withdrawing some staff from its embassy there.
The US took a similar move by ordering relatives of its embassy staff to leave.
But, EU staff are to stay in place for now, with foreign policy chief, Josep Borrell, saying he would not “dramatise” the tensions.
There have also been differences on the support given to Ukraine – the US and UK are among the nations to have sent military aid. However, Germany refused Ukraine’s request for defensive weapons, and will instead send medical aid, German Defence Minister, Christine Lambrecht, told local media.
The Pentagon has said some 8,500 combat-ready US troops are on alert to deploy at short notice.
There are no plans to deploy to Ukraine itself, he added. -BBC