RIYADH: Saudi Arabia is ready to join any ground operation the US-led coalition against the militant Islamic State group in Syria might decide on, a general from the kingdom said on Thursday.

“If there is any willingness in the coalition to go in the ground operation, we will contribute positively in that,” Brigadier General Ahmed al-Assiri told AFP.

Assiri is spokesman for a separate Saudi-led Arab coalition which, since March, has conducted air strikes and ground operations in Yemen.

That coalition supports the government there in its fight against Houthi rebels who seized much of the country.

Saudi Arabia supports certain militant groups against Assad's forces.

Aleppo encircled, militants trapped

Regime troops pressed a major Russian-backed offensive around Aleppo, while Moscow and Ankara traded barbs over the escalating crisis.

As the offensive raged, diplomatic tensions were also rising, with Moscow accusing opposition supporter Ankara of preparing to invade Syria, saying it had spotted troops and military equipment on the border.

The militants' main supply line to Turkey was severed on Wednesday when regime troops broke an opposition siege of two Shia towns, Nubol and Zahraa, on the route to the border.

Regime forces entered the two towns on Thursday to the cheers of residents, who chanted pro-government slogans and showered the fighters with rice.

A high-ranking Syrian government official described the Aleppo advances as important, but said the regime had even more ambitious goals.

“The next objectives are to close the borders with Turkey to prevent the arrival of troops and weapons, then taking Aleppo province, then Idlib province, and finally Idlib city,” he told AFP.

Aleppo city, Syria's former economic powerhouse, has been divided between opposition control in the east and regime control in the west since mid-2012.