Nato has confirmed it is sending additional ships and fighter jets to eastern Europe amid Russia's troop build-up near Ukraine.
Tensions between Russia and the West are currently high and more than 100,000 Russian troops are stationed at various points along its border with Ukraine - a former Soviet state.
Nato said it is beefing up its “deterrence” presence in the Baltic Sea area.
A number of members of the 30-country military organisation have offered troops and equipment.
Denmark is sending a frigate to the Baltic Sea and deploying F-16 war planes to Lithuania.
Spain is sending ships to join Nato’s standing maritime force and considering sending fighter jets to Bulgaria.
France stands ready to send troops to Bulgaria, Nato said.
Nato secretary general Jens Stoltenberg said in a statement: “Nato will continue to take all necessary measures to protect and defend all allies, including by reinforcing the eastern part of the alliance.
“We will always respond to any deterioration of our security environment, including through strengthening our collective defence.”
Intense diplomatic activity has failed to ease tensions and it has emerged today that some British embassy staff and their dependants are being pulled out of Kyiv in response to the mounting Russian threat to Ukraine.
The Foreign Office confirmed the move after the United States ordered the families of all American personnel at the US Embassy to leave the country in response the the risk of an invasion.
The Foreign Office said: “Some embassy staff and dependants are being withdrawn from Kyiv in response to the growing threat from Russia.
“The British Embassy remains open and will continue to carry out essential work.”
The UK believes there is a significant risk that Russian president Vladimir Putin will launch a full-scale invasion of Ukraine.
Foreign Secretary Liz Truss has accused the president of plotting to install a pro-Moscow leader as head of the Ukrainian government.
The Foreign Office took the unusual step of naming former Ukrainian MP Yevhen Murayev as a potential Kremlin candidate to take over in Kyiv – a claim dismissed as provocative “nonsense” by Moscow.
Deputy Prime Minister Dominic Raab warned on Sunday there was a “very significant risk” of a Russian invasion of its neighbour.
“The world needs to keep its eye on this and be very clear with President Putin that it would not do this cost-free, that there would be a price,” he told the BBC.
“A price in terms of the strenuous defence that we would expect the Ukrainians to put up, but also the economic cost through sanctions, which are of course more effective if the international community speaks as one or at least with a broad consensus.”
There are concerns that the crisis could trigger a spike in European energy prices, with The Times reporting that officials fear Russia could restrict supplies of gas in response to sanctions.
