The Jordanian army said it downed a drone heading from Syria on Monday in the third such incident this month, linked to Iran-backed militias.

Meanwhile, officials said an increase in weapons being smuggled across the border was raising concerns about a new Iranian-instigated threat beyond drugs.

The army said in a statement that the drone was brought down in its territory but did not say what it was carrying. Officials have recently revealed weapons were being smuggled as well as narcotics by drone.

Jordanian officials said the increasing use of drones carrying explosives was adding a new dimension in a relentless cross-border billion-dollar drug war the staunch US ally has long blamed on Iranian-backed militias that hold sway in southern Syria.

"This is Iranian targeting of Jordan helped by the presence of their militias near our border. It poses a security threat that goes beyond drugs," Samih Al Maitah, a former minister familiar with developments along the border said.

Syria is accused by Arab governments and the West of producing the highly addictive and lucrative amphetamine captagon and organizing its smuggling into the Persian Gulf, with Jordan a main transit route.

Syrian President Bashar al-Assad's government denies allegations by Jordan and the West of its involvement in drug-making and smuggling, or complicity by Iranian-backed militias protected by its forces.

Jordan, which has intensified military drills along its border with Syria, announced 10 days ago it had foiled a large smuggling operation.

During a visit by the top US general last week, Jordan raised getting more US support for its efforts to curb drug trafficking by Iranian militias, Jordanian officials say.

General Mark Milley, the chairman of the US Joint Chiefs of Staff, confirmed in an interview that Washington was working closely with its ally to provide equipment, training and advice to deal with the growing drug trafficking threat.