British Ambassador to the United Nations Matthew Rycroft speaks during a meeting at the United Nations Security Council on Syria at the United Nations Headquarters in New York City, NY, U.S. April 5, 2017. REUTERS/Shannon Stapleton

UNITED NATIONS (Reuters) - Syrian President Bashar al-Assad has been “put on notice” by the U.S. air strike over a deadly toxic gas attack, Britain’s U.N. Ambassador Matthew Rycroft said on Friday, describing it as a “proportionate response to unspeakable acts.”

“Without Russia’s seven vetoes in the Security Council, defying the views of other members of this council, Assad would have faced sanctions and justice,” Rycroft told the 15-member council.

(This version of the story was corrected to drop ‘not’ from quote in second paragraph)