The Iran nuclear deal has been left hanging by a thread after Tehran announced it would abandon limitations on enriching uranium - a move Germany's Foreign Minister Heiko Maas has warned could be the beginning of the end of the nuclear accord.
The deal to curb Iran's nuclear program in exchange for economic sanctions relief was agreed in 2015 between Iran and six major world powers.
(SOUNDBITE) (English) EUROPEAN UNION FOREIGN POLICY CHIEF FEDERICA MOGHERINI, SAYING: "Today is an historic day." Tehran had already been expected to lay out its latest position on the deal at the weekend.
But after the U.S. drone killing of top Iranian military commander Qassem Soleimani, it coincided with a major escalation of hostilities with Washington.
Tehran has already been overstepping limits on its nuclear activities in response to the U.S. withdrawal from the deal in 2018 and the subsequent reimposition of sanctions that have crippled Iran's oil trade.
European governments have been struggling to rescue the accord.
On Monday (January 6) Britain said Iran's decision was "extremely concerning" and Germany's foreign ministry said it was still working to save the pact.
(SOUNDBITE) (German) GERMAN FOREIGN MINISTRY DEPUTY SPOKESMAN, RAINER BREUL, SAYING: "Our goal remains to save the agreement.
We are in talks on that, above all of course with our British and French partners but also with the Chinese side and the Russian side, those involved in the nuclear deal." EU foreign ministers are expected to meet in Brussels on Friday (January 10) to discuss how to save the deal.
However, observers believe Iran has left the back door open to returning to compliance with the agreement.
Tehran said it would continue to cooperate with the U.N.'s nuclear watchdog and said on Sunday (January 5) it can quickly reverse the steps it is taking is U.S. sanctions are removed.
Meanwhile, U.S. President Donald Trump's advisor Kellyanne Conway suggested he could yet renegotiate a nuclear deal with Tehran.
(SOUNDBITE) (English) COUNSELOR TO THE PRESIDENT, KELLYANNE CONWAY, SAYING: "If Iran wants to start behaving like a normal country and denuclearize, sure, absolutely." Trump took to Twitter on Monday to reiterate the White House stance that Iran will "never have a nuclear weapon" but gave no further details.