London (CNN) -- Foreign Secretary William Hague announced plans Tuesday for the United Kingdom to reopen its embassy in Tehran, Iran, which has been closed since an attack by protesters in 2011 triggered a dramatic breakdown in relations.
Hague's announcement to Parliament follows a series of steps taken by both nations in recent months to improve ties.
In a written statement to lawmakers, he said that, given the progress made, "I have therefore now decided the circumstances are right to reopen our embassy in Tehran.
"There are a range of practical issues that we will need to resolve first. However it is our intention to reopen the Embassy in Tehran with a small initial presence as soon as these practical arrangements have been made."
Hague said his two chief concerns in making the decision had been whether UK Embassy staff would be safe and secure, and whether they would be able to work "without hindrance."
He added, "There has never been any doubt in my mind that we should have an embassy in Tehran if the circumstances allowed. Iran is an important country in a volatile region, and maintaining embassies around the world, even under difficult conditions, is a central pillar of the UK's global diplomatic approach."
The assault by student protesters on the UK Embassy and a separate diplomatic compound in Tehran in November 2011 prompted outrage in the United Kingdom and led Britain to close the embassy's doors and withdraw all its staff from Iran.
Britain also closed the Iranian Embassy in London and ordered all Iranian diplomats to leave.
The protest in Tehran was sparked by anger at UK sanctions imposed against Iranian institutions over Iran's nuclear program. The embassy buildings should have been guarded by Iranian security officers.
Since the election of Iranian President Hassan Rouhani last year, there's been a more positive tone to Iran's interactions with the West.
That relationship has taken on a new significance in light of the current crisis in Iraq, where Sunni militants have seized vast swaths of territory.
Iran, a majority Shiite nation, is an ally of Iraqi Prime Minister Nuri al-Maliki's Shia-led government and has said it would provide help if asked.
The United States, whose formal relations with Iran ended after the 1979 takeover of its embassy there, now faces the politically unpalatable option of cooperating with Tehran to stop gains by the militant group, the Islamic State in Iraq and Syria (ISIS).
The United States and Iran held "very brief discussions" about Iraq and the threat posed by ISIS in Vienna, Austria, on Monday, State Department spokeswoman Marie Harf said.
Deputy Secretary of State William Burns is in Vienna for nuclear talks with Iran.
CNN's Carol Jordan and Elaine Ly contributed to this report.