British Foreign Secretary Jeremy Hunt will visit Iran today for talks on the international agreement aimed at curbing Iran's nuclear programme.
The latest report from the International Atomic Energy Agency - the nuclear watchdog of the United Nations - indicated last week, that, days after fresh US sanctions against Iran took effect, Iran was abiding by the terms of the deal with global powers.
US President Donald Trump dramatically increased pressure on Tehran, withdrawing from the agreement aimed at ending its nuclear programme and introducing several rounds of unilateral sanctions.
Mr Hunt's visit is the first by a Western foreign minister since the United States withdrew from the deal this year.
In a statement, he said: "The Iran nuclear deal remains a vital component of stability in the Middle East by eliminating the threat of a nuclearised Iran".
"It needs 100% compliance though to survive. We will stick to our side of the bargain as long as Iran does.
"But we also need to see an end to destabilising activity by Iran in the rest of the region if we are going to tackle the root causes of the challenges the region faces."
Mr Hunt is due to meet the Iranian Foreign Minister, Mohammad Javad Zarif, for talks on European efforts to maintain relief from nuclear-related sanctions.
He is also due to discuss Iran's role in the conflicts in Syria and Yemen, and the ongoing cases of detained British-Iranian dual nationals.
The Foreign Office in London said that, on Yemen, Mr Hunt would stress concerns about reports that Iran has supplied ballistic missiles and weapons to the Houthi rebels.
Ahead of his visit, Iranian President Hassan Rouhani said the US sanctions on Iran are part of a psychological war launched by Washington against Tehran that will fail.
"America blames us for its failures in the region ... from Yemen to Iraq ... We will not yield to this pressure that is part of the psychological war against Iran," Mr Rouhani said in a speech in the city of Khoy, broadcast live on state TV.
"They have failed to stop our oil exports. We will keep exporting it."
