Iranian Foreign Minister Mohammad Javad Zarif
Iranian Foreign Minister Mohammad Javad ZarifReuters

Iran's foreign minister, Mohammad Javad Zarif, on Wednesday urged world powers to "seize the moment" and drop their "excessive demands" as marathon nuclear talks with the West continued.

"Iran has shown its readiness to engage with dignity and it's time for our negotiating partners to seize the moment," Zarif told reporters in Lausanne, according to AFP.

Iran had shown that it wants "an entente" with the world but it "will not accept submitting to force and excessive demands. Those we are negotiating with should accept this reality," Zarif declared.

The comments came as it was announced that the talks were extended for a second day, even though the original deadline for a framework agreement was Tuesday.

The sides were meant to reach a preliminary accord which would provide an outline for a final deal to be reached by June 30. The preliminary deal was meant to be achieved by midnight on March 31, but the sides are under pressure not to go home empty handed and have thus extended the talks twice already.

The first extension came on Tuesday, hours before the deadline, when State Department spokeswoman Marie Harf said enough progress had been made to warrant an extension, although there still were "several difficult issues" to bridge.

Washington has threatened to walk away from the talks unless the sides could agree on a preliminary framework.

French Foreign Minister Laurent Fabius arrived back in Switzerland to rejoin the negotiations, saying the talks were in the final stretch.

"We are a few meters ... from the finishing line, but we are well aware that the final meters are the hardest," Fabius told reporters, according to AFP.

The stakes were very high, he said, adding that at issue was the question of non-proliferation, and "Iran's reintegration into the international community."

The latest extension comes despite claims Tuesday night by Russia’s Foreign Minister, Sergey Lavrov, that the sides had reached a preliminary agreement and were drafting the text.

Diplomats close to the negotiations rejected Lavrov’s claims as untrue.

Meanwhile, Senator Tom Cotton (R-AR) has demanded that the U.S. walk away from the talks in Lausanne.

"The best solution is walk away from the nuclear negotiations now and return to a position of strength," Cotton said in a statement.

The senator called to "reinstate existing sanctions suspended under the Joint Plan of Action, and Congress should act immediately to impose new sanctions. It’s time for the United States to regain the upper hand and quit negotiating out of weakness."