Tehran (AFP) — A minister from Britain’s Foreign Office arrived in Tehran on Sunday and met with a top diplomat from Iran’s foreign ministry amid escalating regional tensions, state-run IRIB news agency reported.

Minister of State for the Middle East Andrew Murrison spoke with Kamal Kharazi, head of the Strategic Council of Foreign Relations at Iran’s foreign ministry, on “bilateral ties, regional issues” and the 2015 nuclear deal, the agency said.

Murrison is expected to meet deputy foreign minister Abbas Araghchi later on Sunday.

Murrison was to call for an “urgent de-escalation” and raise British concerns “about Iran’s regional conduct and its threat to cease complying with the nuclear deal to which the UK remains fully committed,” according to a statement by Britain’s Foreign Office.

Tensions between Washington and Tehran have flared after Iran on Thursday shot down a U.S. drone.

Iran said the drone violated its airspace — a claim the U.S. denies — near the strategic Strait of Hormuz.

In response, the US was ready to carry out a military strike against Iran but U.S. President Donald Trump said he called it off at the last minute.

The downing of the drone came after tensions spiked between the two countries following a series of attacks on commercial vessels that the US has blamed on Iran — accusations vehemently denied by the Islamic Republic.

Britain is a signatory to the 2015 nuclear deal which saw Iran scale back its nuclear programme in exchange for sanctions relief, but the US unilaterally withdrew from the accord last year and reimposed sanctions.

On May 8, Iran said it would reduce some of its nuclear commitments to the deal unless the remaining partners — Britain, China, France, Germany and Russia — helped it circumvent U.S. sanctions and sell its oil.