By Kylie MacLellan
LONDON (Reuters) -British Foreign Secretary Liz Truss warned Russia on Wednesday that it would be making a "grave mistake" if it attacked Ukraine and said London was working closely with its NATO allies to support Ukraine.
Russian troop movements near Ukraine have triggered concern in the West that Russia might be preparing an invasion.
Russia has repeatedly denied that it is about to attack Ukraine and says it can deploy troops where it wishes on its own territory. It has accused Ukraine and NATO of whipping up tensions.
"I think that would be a grave mistake from Russia," Truss told Reuters when asked about a possible incursion.
"We are very close allies of Ukraine and we are working with out partners in NATO but also directly with Ukraine to make sure they are fully supported," Truss said.
Russia staged military drills in the Black Sea, south of Ukraine, on Wednesday and said it needed to sharpen the combat-readiness of its conventional and nuclear forces because of heightened NATO activity near its borders.
The United States and NATO have signalled their backing for Ukraine in ways that Moscow considers provocative, including through warship manoeuvres this month in the Black Sea and a delivery of U.S. patrol boats to the Ukrainian navy.
(Reporting by Kylie MacLellanEditing by Guy Faulconbridge and Alistair Smout)