UNITED NATIONS (Reuters) - The United States told the United Nations Security Council on Thursday that it was committed to the “permanent destruction” of Islamic State in Syria and would keep pushing for the withdrawal of Iranian-backed forces in the country.

The pledge followed President Donald Trump’s surprise decision to start what will be a total withdrawal of U.S. troops from Syria. Trump declared on Wednesday that the troops had succeeded in their mission to defeat Islamic State, a decision that drew strong criticism from some fellow Republicans and concern among foreign allies.

During a U.N. Security Council meeting on Syria on Thursday, U.S. diplomat Rodney Hunter, the political coordinator of the U.S. mission to the United Nations, did not specifically mention Trump’s decision.

“The United States remains committed to the permanent destruction of ISIS and other terrorist groups in Syria and around the world,” Hunter told the council, using an acronym for Islamic State. “We will use all instruments of our national power to press for a withdrawal of Iranian-backed forces.”

“We will continue to work together with our allies to fight terrorism. The United States will also work with like-minded states, the United Nations, and the Syrian opposition, to seek a diplomatic end to this conflict,” he said.

French U.N. Ambassador Francois Delattre told the 15-member council that the assessment by Paris was that Islamic State continues to be a threat for the Middle East’s Levant region.

“In the upcoming weeks France will be ensuring very carefully that the security of all U.S. partners be ensured, including the Syrian Democratic Forces,” Delattre said.

‘MUCH REMAINS TO BE DONE’

France is a leading member of the U.S.-led coalition fighting militants in Syria and Iraq and has special forces based in the northeast of Syria, deployed alongside Kurdish and Arab forces, and carries out air strikes against the group.

“It is important for the United States to take into account the protection of the people in the northeast of Syria and the stability of this area to make sure that we avoid any new humanitarian tragedy or any resurgence of terrorism,” Delattre said.

Outgoing U.N. Syria envoy Staffan de Mistura, who will step down at the end of the year, made no mention of Trump’s decision during his final briefing of the Security Council.

U.S. special representative for Syria Jim Jeffrey canceled planned meetings at the United Nations on Thursday to discuss the Syria peace process, U.S. officials said.

“Given recent developments, Ambassador Jeffrey will stay in Washington in order to engage with our partners and allies on the way forward in Syria,” a State Department official said.

Jeffrey was named as special representative for Syria in August and told reporters at the time that the United States would not withdraw from Syria until Islamic State had been defeated. He has not commented on Trump’s decision.

Turkey’s Deputy U.N. Ambassador Rauf Alp Denktas told the council his country would continue to combat Kurdish militants, taking “the necessary steps to ensure its border security against the PKK, PYD, YPG threat as and when it deems necessary.” He did not specifically mention Trump’s decision.

The U.S. intervention in Syria began under Trump’s predecessor Barack Obama in September 2014 with air strikes. The Obama administration justified the military action under Article 51 of the U.N. Charter, which covers the individual or collective right of states to self-defense against armed attack.

“We must not lose sight of the threat that Daesh (Islamic State) continue to pose even when they continue no longer to hold territory,” British U.N. Ambassador Karen Pierce told the council.