US Secretary of State Mike Pompeo has threatened to veto any attempts by UN Security Council members to oppose the reintroduction of sanctions on Iran next month. “If any member of the UN Security Council introduces a resolution to continue sanctions relief, the US will oppose it," Mr Pompeo warned in a tweet on Thursday. "If no resolution is introduced, the sanctions on Iran will still return on September 20.” Thirteen of the 15 council members say Washington’s move to reimpose sanctions is void because it is using a process agreed to under a 2015 nuclear deal between Iran and world powers, from which the US withdrew two years ago. In a vote on August 14, only the Dominican Republic sided with the US in calling for an extension of an arms embargo, due to expire in October, against Iran. “Last week, the US triggered the 30-day process to restore virtually all UN sanctions on Iran after the Security Council failed to uphold its mission to maintain international peace and security,” Mr Pompeo said in another tweet. The US says it can trigger the process known as snapback because a 2015 Security Council resolution that enshrines the nuclear deal still names it as a participant. But the president of the Security Council, Indonesian ambassador Dian Triansyah Djani, said on Tuesday that the body was “not in the position to take further action” on the US bid to reintroduce the sanctions on Iran because of a lack of consensus. Several countries outside the council have voiced a desire to return the sanctions, which were lifted under the terms of 2015 nuclear deal, signed by Iran, the US, China, France, Russia, the UK and Germany. On Thursday, German Foreign Minister Heiko Maas met his Israeli counterpart in Berlin and affirmed the need to extend the weapons embargo on Iran. “We are trying to reach a diplomatic solution so that there will be an arms embargo on Iran in the future,” Mr Maas said. Israeli Foreign Minister Gabi Ashkenazi said that an extension was needed to prevent Iran from getting “more advanced weapons systems and spreading them around the Middle East".