WASHINGTON- The United States is expecting to trigger snapback - a return of all U.S. sanctions on Iran - soon, Secretary of State Mike Pompeo said on Wednesday, after the U.N. Security Council rejected Washington's bid to extend an arms embargo on the country.

To trigger a return of the sanctions, the United States will submit a complaint to the 15-member U.N. Security Council about Iran's non-compliance with the nuclear deal, even though Washington quit the accord in 2018.

(Reporting by Humeyra Pamuk and Susan Heavey) ((humeyra.pamuk@thomsonreuters.com; +1 202 3105694; Reuters Messaging: Twitter: @humeyra_pamuk))