A group of top European diplomats on Thursday spoke out against imposing new sanctions on Iran at this time, calling for talks between Western powers and the Islamic Republic to be given an opportunity to succeed.

The call came in an opinion peace in The Washington Post authored by the following diplomats: French Foreign Minister Laurent Fabius, Britain’s Foreign Secretary Philip Hammond, German Foreign Minister Frank-Walter Steinmeier and the European Union’s High Representative for Foreign Affairs, Federica Mogherini.

“In November 2013, after many months of negotiations, the E3+3 (France, Germany and Britain, together with the United States, Russia and China, a partnership also referred to sometimes as the P5+1) and Iran reached an interim agreement on Iran’s nuclear program. This agreement has had three main benefits,” the ministers wrote.

“First, it has stopped the progress of the most sensitive elements of Iran’s nuclear program. Under the Joint Plan of Action agreed to by Iran and the six partners in the talks, which are being coordinated by the European Union, Iran has ceased production of its most highly enriched uranium, limited its production of new centrifuges for enriching uranium and refrained from installing additional centrifuges. Iran has also agreed to cease progress toward bringing on line the nuclear reactor at Arak. As a result, Iran today is further away from obtaining enough fissile material for a nuclear weapon than before the negotiations.

“At the same time, the international community has gained improved access to Iran’s nuclear facilities, allowing the world to verify whether Iran is living up to its commitments. Whereas previous inspections only occurred once every few weeks, the International Atomic Energy Agency is now able to conduct daily inspections of the Natanz and Fordow facilities, and the Arak reactor is now subject to monthly inspections.

“And last but not least, the interim agreement has given us time and space to try to negotiate a long-term settlement to the Iranian nuclear issue, which is critical for the future of international and regional security.”

They go on to warn that, while it was the sanctions imposed on Iran by the West that brought it to the negotiating table, “introducing new hurdles at this critical stage of the negotiations, including through additional nuclear-related sanctions legislation on Iran, would jeopardize our efforts at a critical juncture.”

“While many Iranians know how much they stand to gain by overcoming isolation and engaging with the world, there are also those in Tehran who oppose any nuclear deal. We should not give them new arguments. New sanctions at this moment might also fracture the international coalition that has made sanctions so effective so far. Rather than strengthening our negotiating position, new sanctions legislation at this point would set us back,” wrote the top diplomats.

“Let us be clear: If Iran violates its commitments or proves unwilling to agree to a comprehensive, verifiable understanding that meets the international community’s bottom line, we will have no choice but to further increase pressure on it. For the first time, however, we may have a real chance to resolve one of the world’s long-standing security threats — and the chance to do it peacefully. We can’t let that chance pass us by or do anything to derail our progress,” they added.

Thursday’s editorial comes amid continuing pressure by lawmakers in the United States to pass legislation imposing new sanctions on Iran.

Democratic Senator Robert Menendez and Republican Senator Mark Kirk have introduced legislation that would mandate new sanctions only if a nuclear deal is not reached by March, a timetable that has already been extended past the original November deadline.

Their bill is a toned down version of a previous bill they authored and which had gained momentum in Congress, but which President Barack Obama lobbied hard against and threatened to veto.

Menendez on Wednesday repeated his call for new sanctions on Iran, just hours after Obama used his State of the Union address to argue against them and reiterate again that he will veto such legislation.