Chancellor Angela Merkel (CDU) stands between Boris Johnson (l), Prime Minister of Great Britain, and Emmanuel Macron, President of France, at the beginning of the summit.

The leaders of Germany, France and the U.K. have said they will stand by the Iran nuclear deal, defying a call from President Donald Trump to abandon the 2015 pact.

But they warned Iran that it must comply with the commitments within the Joint Comprehensive Plan of Action (JCPOA), chiefly, the non-proliferation of nuclear weapons.

"Despite increasingly difficult circumstances, we have worked hard to preserve the agreement. All remaining parties to the JCPOA, China, France, Germany, Russia, the United Kingdom and Iran, with the EU as coordinator, have stated their continuing commitment to preserve the JCPOA," the leaders of Germany, France and the U.K. said in a statement issued Sunday evening.

"We urge Iran to reverse all measures inconsistent with the agreement and return to full compliance; we call on Iran to refrain from further violent action or proliferation; and we remain ready to engage with Iran on this agenda in order to preserve the stability of the region.

German Chancellor Angela Merkel, French President Emmanuel Macron and British Prime Minister Boris Johnson said in the statement that "it is essential that Iran return to full compliance with its commitments under the agreement" and expressed "deep concern at the actions taken by Iran in violation of its commitments since July 2019." Iran announced last summer that it had breached the deal by exceeding its stockpile limit of low-enriched uranium.

"These actions must be reversed. We reserve recourse to all the provisions of the JCPOA to preserve it and to resolve the issues related to Iran's implementation of its JCPOA commitments within its framework," the European leaders said Sunday.

The statement comes after EU foreign ministers held an emergency meeting on Friday to discuss heightened tensions in the Middle East and how (and whether) to keep the nuclear deal — dealt a severe blow when the U.S. withdrew from it in May 2018 and reimposed sanctions on Iran — alive.

The summit came after Iranian airstrikes on Iraqi military bases housing U.S. troops, in retaliation for the U.S.' assassination of its top military commander Qasem Soleimani. The meeting happened before Iran's military admitted accidentally shooting down an Ukrainian passenger jet, killing all 176 passengers.

Last week, Trump had said the time had come for Europe to abandon the JCPOA. Speaking Wednesday, Trump said "Nations have tolerated Iran's destructive and destabilizing behavior. Those days are over."

"The time has come for the U.K., Germany, France, Russia and China to … break away from the remnants of the Iran deal or JCPOA."

The leaders said that recent events had highlighted Iran's destabilizing role in the region and said that "its commitment to the security of our allies and partners in the region is unwavering."

"We must address — through diplomacy and in a meaningful way — shared concerns about Iran's destabilizing regional activities, including those linked to its missile programme. We reiterate our readiness to continue our engagement for de-escalation and stability in the region."

They acknowledged Iran's announcement regarding the shooting down of the Ukrainian International Airlines plane and committed "to working with Iran on next steps."