Russian glide bombs and ballistic missiles struck a Ukrainian prison and a medical facility overnight as Russia's relentless strikes on civilian areas killed at least 27 people across the country, officials say.

A Russian airstrike on a prison in a frontline region in southeastern Ukraine has killed 16 people and wounded more than 30 others, according to Ukrainian officials.

Russian airstrikes on a prison and hospital in southeastern Ukraine killed at least 19 people, officials said on Tuesday, while U.S. President Donald Trump said he would start imposing punitive measures on Russia within 10 days if Moscow showed no progress toward ending its war in Ukraine.