Syria's leader Ahmed al-Sharaa told Al Arabiya on Sunday that elections could take four years, noting the importance of ties with Iran and Russia and calling for the United States to lift sanctions.

"The election process could take four years," Sharaa told the Saudi-owned Al Arabiya television, three weeks after his Islamist group Hayat Tahrir al-Sham and allied rebels ousted longtime ruler Bashar al-Assad.

"We need to rewrite the constitution" which could take "two or three years", he added.

In the wide-ranging interview, he expressed hope that the incoming administration of US President-elect Donald Trump would lift sanctions imposed on his now war-torn and impoverished country under Assad.

"The sanctions on Syria were issued based on the crimes that the regime committed," Sharaa said, adding that since Assad was gone, "these sanctions should be removed automatically".

Sharaa's Hayat Tahrir al-Sham (HTS) is proscribed as a terrorist organisation by many governments including the United States.

The leader also noted the importance of ties with Russia and Iran, which were both key allies of Assad.

"Syria cannot continue without relations with an important regional country like Iran, but they must be based on respect for the sovereignty of both countries and non-interference in the affairs of both countries," Sharaa said.

"Russia is an important country and is considered the second most powerful country in the world," he said, noting the "deep strategic interests between Russia and Syria".

"All Syria's arms are of Russian origin, and many power plants are managed by Russian experts... We do not want Russia to leave Syria in the way that some wish," he said.

Sharaa also said local Kurdish-led forces which Turkey opposes would be integrated into the national army.

"Weapons must be in the hands of the state alone. Whoever is armed and qualified to join the defence ministry, we will welcome them," he said.

Based on these criteria, "we will open a negotiations dialogue with the SDF, to perhaps find an appropriate solution," referring to the US-backed, Kurdish-led Syrian Democratic Forces in Syria's north and northeast. (AFP)