Russian Foreign Minister Sergei Lavrov spoke to US Secretary of State Marco Rubio on Wednesday about the preparation of "concrete proposals" for a new round of direct talks with Ukraine, the Russian foreign ministry said.

A statement on the ministry's website said Lavrov told Rubio about the implementation of agreements between the Russian and U.S. presidents during their telephone call a week ago "and preparations by the Russian side of concrete proposals for the next round of direct Russian-Ukrainian talks in Istanbul."

Lavrov earlier said Russia was proposing that the next round of direct talks take place in Istanbul on June 2 with a view to achieving a sustainable peace settlement.

A foreign ministry statement published later on Telegram said Lavrov had spoken by telephone to his Turkish counterpart, Hakan Fidan, with "an exchange of views" about efforts to resolve the Ukraine conflict.

The statement gave no further details. (Reuters)