Russian Foreign Minister Sergei Lavrov in Moscow, Russia August 30, 2018. REUTERS/Maxim Shemetov

MOSCOW (Reuters) - Russian Foreign Minister Sergei Lavrov said on Friday the Syrian government had every right to chase militants out of the rebel-held enclave of Idlib and that talks on establishing humanitarian corridors there were ongoing.

The Syrian province of Idlib and surrounding areas are the last major enclave held by rebels opposed to Syrian President Bashar al-Assad, a close Russian ally. A source has told Reuters Assad is preparing a phased offensive to regain the province.

Syrian government forces “had the full right to protect its sovereignty and to drive out, liquidate the terrorist threat on its territory”, Lavrov was cited as saying by the Interfax news agency.

Tensions between Russia and the West have risen over Idlib, and Russia’s Ministry of Defence announced on Thursday that Russia would begin a major naval exercise in the Mediterranean on Saturday off the Syrian coast.

Lavrov also said that communication between Russia and the United States on Syria is happening in “real time”.

The United Nations has called on Russia, Iran and Turkey to delay a battle that could affect millions of civilians, calling for humanitarian corridors to evacuate civilians.

Russian President Vladimir Putin will attend a three-way summit in Tehran on Sept. 7 with the leaders of Turkey and Iran, his spokesman said on Friday.