The U.S. president told reporters that his Russian counterpart Vladimir Putin wants to "just keep killing people."

The Russian bombardments sent Ukrainians scurrying for shelters across the country and came after the call between Trump and Putin, which ended without a breakthrough.

Russian President Vladimir Putin said on Thursday he was going to speak to U.S. President Donald Trump later in the day.

Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

(Reuters) -Russian air defences shot down four Ukrainian drones headed for Moscow on Saturday, the city's mayor said, while one of the capital's main airports temporarily halted outgoing flights. Mayor Sergei Sobyanin said emergency services were working at the sites of the downed drones,