US President Donald Trump said Monday he is giving Russian President Vladimir Putin 10 to 12 days to stop the killing in Ukraine, shortening a 50-day deadline he had given the Russian leader two weeks ago.

Russia fired an overnight barrage of more than 300 drones, four cruise missiles and three ballistic missiles, the Ukrainian air force said, as the Russian bombardment of Ukrainian cities continued despite Trump's pressure for it to end. U.S.-led peace efforts have also failed to gain momentum.

Trump had said on July 14 that he would implement 'severe tariffs' on Russia unless a peace deal is reached by early September. On Monday, Trump said he would now give Putin 10 to 12 days, meaning he wants peace efforts to make progress by Aug. 7-9.