outside Kurdish-controlled Qamishli has been under the control of Syrian regime throughout the conflict.

Earlier reports suggested Russia had been negotiating a long-term lease of Qamishli airport, which is about 500 kilometres (310 miles) to the north-east of Hmeimim.

Two Mi-35 attack helicopters and a transport helicopter were moved from the Hmeimim base on the Mediterranean to Qamishli airport in northeastern Syria, reported Zvezda television, which is run by the defence ministry.

Russia has begun moving helicopters and other equipment to a new Syrian base on the Turkish border, state TV reported on Thursday, weeks after US forces left the area.

Russia also sent on-ground support, fuel and a meteorological service to Qamishli and has 10 vehicles on the ground to "ensure continuous flights, safety of the helicopters and the defence of this territory", air force official Timur Khodzhayev told the channel.

"The main goal is to ensure calm," he said.

The new base is protected by Russia's Pantsir missile system and the landing area is encircled by military police, according to the channel.

Russia's military is expanding into northeastern Syria following the withdrawal of US forces ordered by President Donald Trump last month, which triggered a Turkish invasion into the Kurdish-populated territory.

The Turks and Russians have since agreed to launch joint patrols in the area to ensure Kurdish forces withdraw from the zone near the Turkish border, which includes Qamishli.

The US previously backed the Kurdish-led Syrian Democratic Forces (SDF) in their fight against the Islamic State group.

Earlier this month the US military met Kurdish officials outside Qamishli, and a source who took part in one of the meetings told AFP that US forces wanted to return to the area.

AFP correspondents also saw a US convoy in a village east of Qamishli on Wednesday.

Pro-Kremlin media has been reporting since late October -- with visible satisfaction -- that Russian forces are moving into areas where American flags once flew.

"We should more actively occupy their bases so that they have nothing to come back to," tweeted defence correspondent Alexander Kots of Komsomolskaya Pravda tabloid.