US Secretary of State Mike Pompeo canceled his trip to Moscow to discuss Iran's threat to pull out of the 2015 nuclear agreement with European officials in Brussels, Reuters reports.
Pompeo was seen boarding a plane at Joint Base Andrews, Maryland Sunday night.
The European officials will discuss Iran's latest threat to pull out of Joint Comprehensive Plan of Action (JCPOA) nuclear deal in 60 days if the European Union does not implement the deal. The United States pulled out the deal last year and levied heavy economic sanctions against the Islamic regime.
Tehran recently threatened to continue enriching uranium if the remaining signatories - China, France, Germany, Russia, and the UK do not keep their promise to protect Iran's oil and banking sectors from US sanctions.
European Union foreign policy chief Federica Mogherini said Monday that the remaining countries intend to stay in the deal.
"We continue to fully support the nuclear deal with Iran, its full implementation. We will have also today, at the margins of the Foreign Affairs Council, a meeting between myself and the foreign ministers of France, Germany and the UK to discuss how to best support the full implementation, continue to support the full implementation of the nuclear deal with Iran. That for us remains a key pillar of security in our region and it has been and continues to be for us a key element of non-proliferation, the non-proliferation architecture globally and in the region. So, we will continue to support it as much as we can with all our instruments and all our political will," she said.
However, the European Union strongly condemned Iran's latest ultimatum.
"We strongly urge Iran to continue to implement its commitments under the JCPOA in full as it has done until now and to refrain from any escalatory steps," a statement read.
"We reject any ultimatums and we will assess Iran's compliance on the basis of Iran's performance regarding its nuclear-related commitments under the JCPOA."
The United States responded to Iran's new threats by announcing more sanctions on Iran's aluminum, copper, iron, and steel sectors.
This comes during increased tension between the United States and Iran.
Last Sunday, US National Security Advisor John Bolton announced the US had sent the USS Abraham Lincoln Carrier Strike Group and a bomber task force to the Middle East to "send a clear and unmistakable message to the Iranian regime."
Bolton said the US is not seeking a war with Iran, "but we are fully prepared to respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps, or regular Iranian forces."
Axios reported that Israel warned the US off to the possibility of an Iranian attack on US interests in the Gulf before Bolton sent the carrier and bomber task force.