Syria's interim President Ahmed Sharaa said mass killings of members of ousted President Bashar al-Assad's minority sect were a threat to his mission to unite the country, and promised to punish those responsible, including his own allies if necessary.

In his first interview to a global news agency, held after hundreds died in four days of clashes between Alawite Muslims and Syria's new Sunni Islamist authorities, Sharaa blamed pro-Assad groups backed by foreigners for triggering the bloodshed but acknowledged that revenge killings had followed.

"Syria is a state of law. The law will take its course on all," he told Reuters from the Damascus presidential palace, where Assad resided until Sharaa's forces toppled him on December 8, forcing the ousted ruler to flee to Moscow.

"We fought to defend the oppressed, and we won't accept that any blood be shed unjustly, or goes without punishment or accountability, even among those closest to us," Sharaa said.

In a wide-ranging interview, Sharaa also said that his government had had no contacts with the United States since President Donald Trump had taken office. He repeated pleas for Washington to lift sanctions imposed in the Assad era.

He also held out the prospect of restoring relations with Moscow, Assad's backer throughout the war, which is trying to retain two major military bases in Syria.

He rejected criticism from Israel, which has captured territory in southern Syria since Assad was toppled. And he said he aimed to resolve differences with Kurds, including by meeting the head of a Kurdish-led group long backed by Washington.

While he blamed the outbreak of violence in recent days on a former military unit loyal to Assad's brother and an unspecified foreign power, he acknowledged that in response "many parties entered the Syrian coast and many violations occurred".

"It became an opportunity for revenge" for years of pent-up grievances, he said, although he said the situation had since been largely contained.

Sharaa said 200 members of the security forces had been killed in the unrest, while declining to say the overall death toll pending an investigation, which will be conducted by an independent committee announced on Sunday before his interview.

A UK-based war monitoring group, the Syrian Observatory for Human Rights, said that as of Sunday night as many as 973 Alawite civilians had been killed in revenge attacks, after fighting in which more than 250 Alawite fighters and more than 230 members of the security forces had died.

'MY CHEST TIGHTENS IN THIS PALACE'

After years in the field at the helm of a guerrilla movement that broke off from Al Qaeda, the 42-year-old son of an Arab nationalist was soft-spoken. His voice sometimes barely registered above a whisper during the interview, held after midnight on Monday during the holy month of Ramadan when business is often conducted late.

His entourage of young, bearded men appeared to still be adjusting to protocol in the opulent seat of power.

"To be honest, my chest tightens in this palace. I'm astonished by how much evil against society emanated from every corner," Sharaa said.