Belarus says its military conducted exercises in the country on Tuesday and Wednesday. This could heighten concern that an ally of Russia might join the invasion of Ukraine.

The Belarusian Defense Ministry announced the start of the drills on Tuesday. It said they had been previously planned, and that the military confirmed alignments between officers commanding the entire military and personnel tasked with logistics support.

Before the invasion of Ukraine, Russia sent 30,000 troops to Belarus for what it called joint exercises.

The US Defense Department said those troops crossed into Ukraine from February 24.

Some observers say Belarus could use the drills to join the invasion as the Russian military is facing stiff resistance from Ukrainian forces.

The British Defense Ministry said on Wednesday that Russian units suffering heavy losses were withdrawing to Belarus and Russia to reorganize.

But the US Defense Department says the Belarusian military has so far shown no signs of joining the invasion, such as movements to near the border.