Senior European diplomats have urged the United States not to kill off the 2015 nuclear deal with Iran.

U.S. President Donald Trump is facing a Friday deadline to decide how to proceed and the White House is due to make an announcement.

After a meeting of European diplomats in Brussels on Thursday, French Foreign Minister Jean-Yves Le Drian said Paris remained dedicated to the agreement.

"All parties should uphold the deal," he said, according to CNN. "It is also necessary that our U.S. allies do the same and should be seen doing the same," Le Drian said after meeting with his Iranian, British, German and French counterparts.

Iranian Foreign Minister Javad Zarif said there was "strong consensus" on the deal but warned that Iran's continued compliance to the agreement depended on that of the United States.

Iranian Foreign Minister Zarif says "any move that undermines JCPOA is unacceptable".

The nuclear agreement was brokered by the Obama administration -- along with the European Union, Germany, Russia, China, France, and the UK.

Under the nuclear deal, Iran is obliged to limit its nuclear program in exchange for termination of nuclear-related sanctions.

Iran has threatened to surprisingly speed up its nuclear enrichment activities if the nuclear deal is ditched. 

“Iran is ready to increase the speed of its nuclear activities in various areas, especially enrichment, several times more than the pre-JCPOA era,” asserted Behrooz Kamalvandi, the deputy chief of the Atomic Energy Organization of Iran.  

Majid Takht-Ravanchi, who was involved in crafting the nuclear deal, has also said, “We are ready for any situation especially the worst scenario on the JCPOA and we have made planning in a way that the U.S. will be surprised by the speed of our response.” 

Thursday's meeting in Brussels was convened by EU foreign policy chief Federica Mogherini.

"The deal is working, it is delivering on its main goal which means keeping the Iranian nuclear program in check and under close surveillance," Mogherini said after the meeting. "Iran is fully complying with the commitments made under the agreement."

British Foreign Secretary Johnson calls the nuclear agreement a "considerable diplomatic accomplishment".

Zarif said the Iranian people "have every right" to all the "dividends" resulting from the Joint Comprehensive Plan of Action (JCPOA), the official name for the nuclear deal.
"Any move that undermines JCPOA is unacceptable," he said in a post on his official Twitter feed. He added that the European parties are "fully aware that Iran's continued compliance (is) conditioned on full compliance by the US."

The deal is one of several foreign policy issues where Europe's most powerful economies stand in opposition to the Trump administration. European countries are banking on the deal, as many began investing in Iran after the sanctions were lifted.

It will be politically difficult for Trump to walk away from the deal without proving Iran has violated the agreement. 

UK Foreign Secretary Boris Johnson insisted that Iran had not violated the deal, citing the International Atomic Energy Agency's assessment. He called the agreement a "considerable diplomatic accomplishment."

"I want to stress that I don't think anybody has so far produced a better alternative as a way of preventing the Iranians from going ahead with the acquisition of its nuclear capability," he said, challenging the deal's opponents to come up with a better solution.

"It is also clearly important to build worldwide support for this deal, that Iran should be able to show that it is a good neighbor in the region."

Germany Foreign Minister Sigmar Gabriel also said, "It would send a very dangerous signal to the rest of the world if the only agreement which prevents us from the proliferation of nuclear weapons would be negatively affected."