Russian President Vladimir Putin called US President Barack Obama on Thursday to discuss the conflict in Ukraine as well as ISIS and the crisis in Syria, the White House said on Thursday night.
In a statement, the White House said the two leaders addressed the Syrian crisis and agreed on the importance of unity among six world powers that are negotiating to secure a final deal with Tehran on June 30.
The crisis in eastern Ukraine has led to the worst standoff between Russia and the West since the Cold War. The US said it would deploy heavy military equipment for the first time in the Baltics and Eastern Europe to deter further Russian aggression in Europe.
The White House said it was Putin who initiated the phone call with Obama.
"President Obama reiterated the need for Russia to fulfill its commitments under the Minsk agreements, including the removal of all Russian troops and equipment from Ukrainian territory," it said in a statement.
The US announcement followed comments by a NATO commander on Monday claiming there has been a continuous flow of ammunition and other military supplies from Russia across the border to Ukraine.
Obama and Putin also engaged in a detailed exchange of opinions concerning the situation in Syria.
"The leaders discussed the increasingly dangerous situation in Syria, and underscored the importance of continued P5+1 unity in ongoing negotiations to prevent Iran from acquiring a nuclear weapon," the White House said.