The Turkish forces have brought in 2,000 military vehicles into northern Syria over the past 12 days, a war monitor reported on Saturday.

The Turkish army has been bringing the military reinforcement into areas controlled by the Turkey-backed rebels in the countryside of Idlib and Aleppo provinces in northern Syria, according to the Syrian Observatory for Human Rights.

The Britain-based watchdog group said that around 6,500 Turkish soldiers were deployed in parts of Idlib and Aleppo at the same time.

The latest military convoy of 50 vehicles entered Syria after midnight Saturday, said the observatory.

The military reinforcement of Turkey comes at a time when the Syrian army managed to capture key areas in both provinces over the past two months.

Syria has waged a crescendo of condemnation against Turkey for backing the rebel groups.

On Friday, Syria's Deputy Foreign Minister Faisal Mekdad told the Lebanese al-Mayadeen TV that Turkey has become an "enemy state" to Syria, because "it occupies Syrian territory and bring in terrorists."

He added that confronting the Turkish and U.S. "occupation" in Syria is a "sovereign right."

The US had repeatedly announced its military withdrawal from Syria. However, American troops are still present there. US President Donald Trump announced the fall of the Islamic State's five-year "caliphate" in March 2019, and added that the US would "remain vigilant until [IS] is finally defeated".

A convoy of US military vehicles has arrived from Iraq to Al-Hasakah province in northeastern Syria, Sham FM broadcaster reported.

According to its post on Facebook, at least 55 vehicles, including tanks and engineer equipment, entered the province from Iraq. 

US forces stationed in Syria reportedly started the construction of a new military base in the oil-rich Al-Hasakah province. According to the Turkish Anadolu news agency, which cited its sources, the equipment and materials for the construction arrived from Iraq via the al-Waleed border crossing. The agency suggested that the base was built not to let Russian forces, lawfully deployed in Syria, reach the Rmelan oil field. 

Turkey has no intention of invading Syriaq

Turkish President Recep Tayyip Erdogan said on Saturday that Turkey has "no intention to invade or annex the Syrian territory."

Speaking at an event of his ruling party in Istanbul, Erdogan noted that the problem in Idlib, the last rebel-held stronghold in Syria, would not be resolved until the government forces are drawn to the limits set by the Sochi deal.

"Otherwise, we will handle it before the end of February," the Turkish president stressed.

Earlier in the day, Erdogan and U.S. President Donald Trump exchanged views by phone on ending the crisis in Idlib as soon as possible, Turkey's Directorate of Communications announced on Twitter.

The two leaders agreed that the attacks of the Syrian government forces against the Turkish soldiers in Idlib were unacceptable.

On Monday, five Turkish soldiers were killed and five others wounded in a Syrian government forces' artillery attack in Idlib.

Earlier in February, the Syrian forces killed eight Turks, including five soldiers, in another artillery offensive in the region.