(VOVworld) - Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry spoke on the phone on Sunday about closer cooperation between their countries' militaries on the Syria ceasefire plan.

U.S. Foreign Secretary John Kerry and Russian Foreign Minister Sergei Lavrov (L) go for a handshake before their bilateral talks in Munich, Germany, February 11, 2016, ahead of the International Syria Support Group (ISSG) meeting (Photo: Reuters)

The two sides also protested attempts to release provocative information on breaking the ceasefire in Syria. Syria’s ceasefire mediated by Russia and the US, took effect on February 27. The ceasefire involves the government and opposition groups but excludes the Islamic State and al-Nusra Front groups, which have links to al-Qaeda. Nearly 100 opposition groups in Syria have agreed to respect the ceasefire.