U.S., Britain, France make case at U.N. for Syria strikes

(Recasts throughout, adds U.S., Russian, French, British comments)

By Michelle Nichols

UNITED NATIONS, April 13 (Reuters) - The United States, France and Britain made the case at the United Nations on Friday for military action against Syria after a suspected deadly chemical weapons attack, though U.S. envoy Nikki Haley warned that "you don't rush decisions like this."

The U.N. Security Council met for the fourth time this week on Syria as U.S. President Donald Trump considers military action over the alleged gas attack by government forces on the town of Douma last Saturday, which killed dozens of people.

"Our president has not yet made a decision about possible action in Syria," Haley said. "But should the United States and our allies decide to act in Syria, it will be in defense of a principle on which we all agree.

"All nations and all people will be harmed if we allow (Syrian President Bashar) Assad to normalize the use of chemical weapons," she said, adding that Washington estimated Assad had used toxic gas at least 50 times during the seven-year war.

U.N. Secretary-General Antonio Guterres said international chemical weapons experts have arrived in Syria to determine whether chemical weapons were used, but not who is to blame. An international inquiry to establish responsibility for such attacks, set up by the Security Council in 2015, ended in November after Russia blocked three attempts to renew it.

Given the Security Council deadlock, about 45 human rights and aid groups urged Guterres on Friday to appoint a team of investigators to determine blame for toxic gas attacks in Syria.

Russia and Syria have said there was no evidence of a chemical weapons attack in Douma. Russian U.N. Ambassador Vassily Nebenzia appealed for the United States, France and Britain to reconsider military action.

"The sole thing they have an interest in is to oust the Syrian government and more broadly to contain the Russian Federation," Nebenzia said.

French U.N. Ambassador Francois Delattre said: "The (Syrian) regime has reached a point of no return. France will shoulder its responsibility to end an intolerable threat to our collective security."

Any countries that carry out a strike on Syria over the use of chemical weapons could defend the action under Article 51 of the U.N. Charter, which covers an individual or collective right to self-defense against armed attack, diplomats said.

Guterres urged all states "to act responsibly in these dangerous circumstances."

Russia has vetoed 12 U.N. Security Council resolutions on Syria since 2011, several with the support of China.

"It is not only dangerous what Russia is doing in vetoing our resolutions and supporting the Syrian regime's actions against its own people, it is ultimately prejudicial to our security, it will let Daesh (Islamic State) re-establish itself," British U.N. Ambassador Karen Pierce told the council.

(Reporting by Michelle Nichols Editing by Chizu Nomiyama and Dan Grebler)