Foreign Secretary William Hague says Britain and Iran have begun a process that could lead to the reopening of their embassies after diplomatic relations broke down in 2011.
Hague told Parliament on October 8 that he and his Iranian counterpart, Mohammad Javad Zarif, had agreed on gradual steps to mend ties.
He said that the two countries will first appoint a nonresident charge d'affaires tasked with gradually building relations, which will eventually lead toward the reopening of embassies of both countries.
"Our diplomatic relations suffered a severe setback when our embassy compounds in Tehran were overrun in 2011 and the Vienna Convention flouted and when the Iranian Majlis [parliament] voted to downgrade relations with the U.K.," Hague said.
"It is understood on both sides that given this history, progress in our bilateral relationship needs to proceed on a step-by-step and reciprocal basis."
Iran's semiofficial ISNA news agency quoted Foreign Ministry spokeswoman Marzieh Afkham as confirming that Tehran had agreed to the appointment of nonresident charges d'affaires in both countries.
The ransacking of the British Embassy in Tehran in 2011 led to one of the worst diplomatic crises between the two countries since Iran's Islamic Revolution in 1979.
'Concrete Steps' Needed
Hague noted that the tone of discussions with Tehran had changed since the election of President Hassan Rohani in June.
"We must not underestimate the difficulties ahead. Iran has a complex power structure, there are voices in Iran who do not agree with their government's stated desire to see progress on nuclear negotiations and rapprochement with the West and improvements in our bilateral relations will require confidence on both sides that those improvements can be sustained," Hague added.
"But to be open to such improvement is consistent with our desire to find a peaceful resolution to the nuclear dispute and the fact that we have no quarrel with the people of Iran."
Hague, however, said that the future of British-Iranian relations would depend on concrete steps by both sides.
He added that Tehran would need to make fundamental changes to its nuclear program if it wanted the international community to ease sanctions.
"We must not forget for one moment that as things stand today, Iran remains in defiance of six UN Security Council resolutions and of multiple resolutions of the International Atomic Energy Agency board of governors and is installing more centrifuges in its nuclear facilities," he said.
"In the absence of change to these policies, we will continue to maintain strong sanctions. A substantial change in British or Western policies requires a substantive change in that program."
The West suspects that Iran wants to obtain a nuclear weapon. Tehran denies the charge.
With reporting by Reuters and AFP