NEW YORK - The United States was further isolated on Friday over its bid to reimpose international sanctions on Iran with 13 countries on the 15-member UN Security Council expressing their opposition, arguing that Washington’s move is void given it is using a process agreed under a nuclear deal that it quit two years ago.

READ MORE: Chinese UN mission says US' 'snapback' demand 'groundless'

In the 24 hours since US Secretary of State Mike Pompeo said he triggered a 30-day countdown to a return of UN sanctions on Iran, including an arms embargo, long-time allies Britain, France, Germany and Belgium as well as China, Russia, Vietnam, Niger, Saint Vincent and the Grenadines, South Africa, Indonesia, Estonia and Tunisia have already written letters in opposition, seen by Reuters.

Dominican Republic has not yet written to the UN Security Council to state its position on the sanctions snapback push

The United States has accused Iran of breaching a 2015 deal with world powers that aimed to stop Tehran developing nuclear weapons in return for sanctions relief. But US President Donald Trump described it as the “worst deal ever” and quit in 2018.

Diplomats said Russia, China and many other countries are unlikely to reimpose the sanctions on Iran. Pompeo again warned Russia and China against that on Friday, threatening US action if they refuse to reimpose the UN measures on Iran.

The United States acted on Thursday after the Security Council resoundingly rejected its bid last week to extend an arms embargo on Iran beyond its expiration in October. Only the Dominican Republic joined Washington in voting yes.

ALSO READ: US triggered a 'snapback' of sanctions on Iran, what now?

Dominican Republic has not yet written to the council to state its position on the sanctions snapback push.

Under the process Washington says it has triggered, it appears all UN sanctions should be reimposed at midnight GMT (8 pm New York time) on Sept 19 -- just days before Trump is due to address world leaders at the UN General Assembly, the annual meeting that will be largely virtual because of the coronavirus pandemic.