Further 350 British troops to be sent to Poland

The deployment is in addition to 100 British troops sent to Poland last year to help support it with a migrant crisis at its border with Belarus.

At a news conference with his Polish counterpart Mariusz Błaszczak in London, Wallace said the two had met to discuss what could be done to deter Russia from a potential invasion of Ukraine.

Russia has deployed more than 100,000 troops near Ukraine's borders. It denies planning an invasion, but says it is ready to take unspecified military action if its demands are not met, including a promise by NATO never to admit Ukraine and to withdraw some troops from Eastern Europe.

Wallace said the international reaction to a Russian invasion of Ukraine would be severe sanctions, isolation, and "more NATO" in eastern Europe, adding that "no one wants to divide and rule Russia".

Błaszczak said historical experience showed that only decisive deterrence could prevent Russian aggression, and that there were "many examples" in history of appeasement encouraging aggression between countries.

The United States and its allies have ruled out defending Ukraine with military force but say they would respond to any invasion with sanctions, arms sales and reinforcement of NATO countries nearby.

Last week U.S. President Joe Biden ordered nearly 3,000 U.S. troops to deploy in Poland and Romania to better protect NATO's eastern flank.