The US military said Friday it was repositioning a squadron of F-16 war planes from Germany to Romania, "to reinforce regional security" in the midst of flaring tensions with Russia over Ukraine.

Without specifying how many F-16s were being moved, the command of the US Air Forces in Europe said the planes would arrive Friday at the Romanian air base of Fetesti, less than 60 miles (100 kilometers) from the Black Sea, where they will join Italian combat aircraft that are already deployed there.

The aircraft and crews will "work closely with allies in the Black Sea region to reinforce regional security during the current tensions caused by Russia's military build-up near Ukraine," the US command, which is based in Germany, said in a statement.

They will be responsible in particular for protecting NATO airspace in the region close to Crimea, which Russia annexed from Ukraine in 2014.

On Thursday, the US Air Force announced the arrival in Britain of B-52 strategic bombers for "long-planned" maneuvers, while the US Navy announced the deployment in the European theater of four destroyers to reinforce the US Sixth Fleet.

US President Joe Biden has sent 3,000 US troops to Germany, Poland and Romania to bolster allies on NATO's eastern flank, as Western states fear a Russian invasion of Ukraine.

The move comes as Russia began large-scale military drills in Belarus, right on the border with Ukraine, which is at the center of high tensions between Russia and the West, and as intense diplomatic efforts to defuse the crisis appear to be making little headway.