Western allies have 15 months to unify against Iran before the regime is free to buy and sell weapons under the 2015 nuclear deal, according to Secretary of State Mike Pompeo.

“Time is drawing short to continue this activity of restricting Iran’s capacity to foment its terror regime,” Pompeo said Tuesday at the United Nations Security Council.

The top U.S. diplomat paired that exhortation with the launch of a State Department “countdown clock” to the expiration of the United Nations arms embargo on Iran and the lifting of travel restrictions on Islamic Revolutionary Guard Corps Gen. Qassem Soleimani next year. President Trump’s withdrawal from the nuclear deal has been a divisive issue among Western allies, but the U.S. presentation put a spotlight on the weapons systems that alarm key European powers.

“Soon after, the Iranian regime will also be free to sell weapons to anyone, including terrorist proxies, and countries like Russia and China will be able to sell the Iranian regime tanks, missiles, and air defense equipment,” Pompeo’s team emphasized in a note alongside the countdown clock. “This could start a new arms race in the Middle East and further destabilize the region and the world.”

The council meeting, billed as a wide-ranging discussion of Middle East security issues, recalled some of the key themes of the debate that took place last year in the lead-up to Trump’s decision to exit the agreement. European envoys, such as the United Kingdom’s Karen Pierce, stressed that they see “no alternative” to the nuclear pact. Pompeo recited a litany of Iranian aggression in the Strait of Hormuz this summer, which drew more agreement, but even then European allies seemed wary of being dragged into a plan to counter Iran that they deem hasty or imprudent.

“We do this through political dialogue, and, if need be, through coordinated sanctions,” Andreas Michaelis, a German deputy foreign minister, told the council after Pompeo spoke. “We are convinced that active deescalation by all sides will yield positive results and that an even higher pressure and unilateral actions will do the opposite.”

Pompeo acknowledged that “greater cooperation in the Middle East is needed more than ever,” as a preface to touting a diplomatic process launched earlier this year in Warsaw. European leaders hesitate to attend the ministerial in February, in order to avoid antagonizing Iran, but Pompeo encouraged them to attend a series of working groups scheduled to take place this fall.

“We need fresh thinking to solve old problems,” he said. “No one country will be the subject of these discussions. All nations will be heard and all voices will be respected.”