Syria will join the international coalition to combat the Islamic State group, marking a shift in US foreign policy in the Middle East, a senior Trump administration official confirmed to CBS, the BBC's US media partner.

The announcement came as President Donald Trump met Syrian President Ahmed al-Sharaa at the White House - the first such visit from a Syrian leader in the country's history.

Diplomatic relations between Syria and the US have been suspended since 2012, although Trump has moved to restore them after the fall of the regime of Bashar al-Assad.

Trump has expressed his support for al-Sharaa, who until recently was designated a terrorist by the US government.

Speaking to reporters in the Oval Office several hours after the meeting, Trump said that we want to see Syria become a country that's very successful.

He added, And I think this leader can do it. I really do. Trump noted that more announcements are forthcoming, although he provided no details.

This is the third meeting between the two leaders, following one in May on the sidelines of the Gulf Cooperation Council and a dinner during the UN General Assembly in September.

Al-Sharaa's visit to the White House caps a remarkable re-branding for the former jihadist. Not long ago, he led a branch of Al-Qaeda - the group behind the 9/11 attacks and many others - before breaking off ties.

Even until this year, he was the leader of Hayat Tahrir al-Sham, an armed Islamist group which the US officially considered a terrorist organisation until four months ago, with a $10m bounty on his head.

The Treasury Department removed al-Sharaa from its specially designated global terrorist list just last week.

But since becoming interim Syrian president, al-Sharaa has worked to soften his public image as he tries to rebuild Syria, with foreign support, following 13 years of war.

He has had a rough past, Trump said on Monday. And I think, frankly, if you didn't have a rough past, you wouldn't have a chance.

Al-Sharaa's rule, however, has been marred by killings of members of Syria's Alawite minority, as well as by deadly violence between Sunni Bedouin fighters and Druze militias.

He has vowed to root out members of his security forces that have committed human rights violations.

Trump, for his part, has repeatedly expressed support for al-Sharaa, referring to him as a young, attractive guy and a fighter with a strong past.

In June, President Trump signed an executive order lifting sanctions against Syria, which the White House said would help support the country's path to stability and peace.

At the time, the administration said it would monitor the new Syrian government's actions, including taking steps toward normalising ties with Israel and addressing foreign terrorists and militant groups operating in the country.