According to the Kremlin, the two leaders "agreed that the sharp political standoff can only be resolved by peaceful means."
Putin's office also noted that he underlined to the British prime minister "the paramount importance" of the Geneva Statement's implementation, and suggested that Ukraine's central government is responsible for de-escalating the crisis.
Under the terms of the April 17 Geneva accord, Ukraine and Russia agreed that all illegal military entities be disbanded, all occupants of seized buildings disarmed and evacuated, and all protesters granted amnesty.
Since the agreement was reached, however, pro-Russian militants have detained journalists, reportedly abducted OSCE military monitors, Russia continues to amass troops near the border of Ukraine, and the Russian defense ministry ordered military drills along the border as a response to Ukraine's anti-terror operations.
There was no available comment from 10 Downing Street.
Notable deaths of 2014 [PHOTOS]