Tehran must take concrete steps to curb its nuclear program or risk the reimposition of U.N. “snapback” sanctions, the European Union’s foreign policy chief said on Tuesday.

“Diplomacy has a chance. The deadlines are running, and let’s see. We need to see some real action also on the Iranian side,” said Kaja Kallas.

Earlier on Tuesday, the foreign ministers of France, Britain and Germany—the so-called E3—met with their Iranian counterpart on the sidelines of the U.N. General Assembly in New York, joined by Kallas.

“In light of the unjustified and illegal move to begin reinstating the U.N. Security Council’s sanctions, some ideas and proposals for continuing diplomacy were raised during the meeting, and it was agreed that consultations will continue,” Iran’s Foreign Ministry said in a statement on Tuesday.

Hours later, Reuters reported, citing a French diplomatic source, that Tehran has yet to meet the conditions to avert the reimposition of U.N. sanctions.

“But discussions will continue to explore all possibilities to the fullest,” the source was cited as saying. “We remain mobilized until the last moment. The ball is in Iran’s court.”

On Aug. 28, the E3 launched a 30-day process to reimpose U.N. sanctions, accusing Tehran of failing to comply with the 2015 deal designed to prevent it from developing nuclear bombs.

The European powers have offered to delay the reinstatement of sanctions for up to six months to allow room for talks on a long-term deal, provided Tehran restores access for U.N. nuclear inspectors, addresses concerns over its stockpile of enriched uranium and enters negotiations with the United States.

Iranian Supreme Leader Ali Khamenei on Tuesday rejected direct negotiations with the Trump administration, calling the prospect “a sheer dead end.

“The U.S. has announced the results of the talks in advance. The result is the closure of nuclear activities and enrichment. This is not a negotiation. It is a diktat, an imposition,” Khamenei said, according to the Associated Press.

The U.N. Security Council on Friday voted down a resolution to provide sanctions relief to the Islamic Republic.

Under UNSC Resolution 2231, which codified the 2015 Iran nuclear deal—formally known as the Joint Comprehensive Plan of Action—nine Security Council members would have had to vote to lift sanctions on Iran after the E3 initiated the process to trigger the “snapback” mechanism.

Only four members of the council—Algeria, China, Pakistan and Russia—backed Iran during the vote.

As a result, absent further action from the Security Council, U.N. nuclear sanctions on Iran will be reimposed on Sept. 27.

Gideon Sa’ar, Israel’s foreign minister, welcomed the development on Friday, stressing that “Iran’s nuclear program is not intended for peaceful purposes.

“A nuclear-armed Iran would mean that the most dangerous regime possesses the most dangerous weapon, dramatically undermining global stability and security,” he continued. “The international community’s goal must remain unchanged: to prevent Iran from ever acquiring nuclear capabilities.”