Russian Foreign Minister Sergei Lavrov and United States Secretary of State John Kerry have agreed to meet in Zurich on January 20 for talks on Syria and Ukraine, the Russian foreign ministry said Thursday.

During a telephone call, "Lavrov and Kerry agreed to hold a personal meeting on January 20 in Zurich," the ministry said in a statement.

The foreign affairs chiefs in their conversation "continued examining ways to resolve the Syrian crisis and the conflict in Ukraine," the ministry said.

It said Kerry and Lavrov were talking "on the instructions of the Russian and US presidents" after Vladimir Putin and Barack Obama spoke by telephone on Wednesday about the crises in Syria and Ukraine.

Putin and Obama discussed the "effort to try to bring about a political transition inside of Syria," said White House spokesman Josh Earnest.

"Both the United States and Russia have a vested interest in seeing that occur."

The United Nations envoy for Syria, Staffan de Mistura, said Wednesday that the permanent Security Council members -- Britain, China, France, Russia and the United States -- had pledged to take "immediate action" to push for deliveries of aid to besieged areas of Syria.

In December, the UN Security Council unanimously adopted a resolution endorsing a peace process to end the nearly five-year war in Syria, without touching on the contentious issue of the fate of Syrian President Bashar al-Assad.

Putin and Obama, while speaking on Wednesday, also "spent a significant portion of their time discussing the need for the Russians to live up to the commitments that they made in Minsk -- to end their support for separatists that are destabilising Ukraine right now," said Earnest.