Vladimir Putin calls Barack Obama to discuss Ukraine, Islamic State group: White House

Washington: Russian President Vladimir Putin called his US counterpart Barack Obama on Thursday to discuss the conflict in Ukraine, the Islamic State group's advances and a deal on Iran's nuclear program.

The crisis in Ukraine has triggered the worst standoff between Russia and the West since the Cold War, and the US said earlier this week it would deploy heavy weapons in central and eastern Europe for the first time.

The US announcement followed promises by NATO on Monday to step up its military presence in eastern Europe, against the backdrop of the conflict in Ukraine.

Putin, who has consistently denied backing the pro-Russian rebels in Ukraine, initiated the phone call with Obama, according to the White House.

"President Obama reiterated the need for Russia to fulfil its commitments under the Minsk agreements, including the removal of all Russian troops and equipment from Ukrainian territory," it said in a statement.

The crisis in Ukraine has killed 6,500 people in a little over a year and a peace deal struck in Minsk, Belarus has unravelled.

Obama and Putin also discussed Syria, where the self-proclaimed Islamic State group has made rapid gains, as well as historic negotiations between world powers and Iran over its disputed nuclear program.

"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.