Russia intends to step up its military involvement in Syria to prevent the "imminent" collapse of the Syrian regime, the EU's foreign policy chief has told Al Jazeera.

Federica Mogherini's comments on Saturday follow reports that 500 Russian troops have been deployed to a forward operating base in the Syrian port city of Latakia.

In an interview with Al Jazeera's James Bays for Talk to Al Jazeera, the EU's high representative for foreign affairs and security policy said that Russia's Foreign Minister Sergei Lavrov told her his country wanted to prevent the collapse of the Syrian state.

"His fear is of a complete collapse of the state structures in Syria; this could be one of the reasons Russia is talking in this way, but it could also be willingness to show that Russia is an important, substantial player," Mogherini said.

Bays said EU and US leaders meeting at the UN headquarters in New York were divided on what role Syrian President Bashar al-Assad, a close ally of Russia's Vladimir Putin, would play after any future settlement.

"There are different views among European leaders and some, including the UK, have floated the idea that perhaps Assad could stay on for a transitional period."

The US and the EU have also approached Iran to help find "a solution to the Syrian conflict".

US Secretary of State John Kerry and Mogherini discussed the issue with the Iranian Foreign Minister Mohammad Javad Zarif on the sidelines of the UN General Assembly in New York.

Russian military shipments to Syria have "alarmed" the US and its allies in recent weeks, and Putin is expected to defend them in a UN speech on Monday.

US President Barack Obama and Putin are set to meet at the sidelines of Monday's UN meeting to discuss the situations in Syria and Ukraine.

PHOTO CAPTION

A satellite image with annotations provided by GeoNorth, AllSource Analysis, Airbus shows Russian transport aircraft, helicopters, tanks, trucks and armed personnel carriers at an air base in Latakia province, Syria. Russia on Thursday, Sept. 17, 2015.

Al-Jazeera