A British Parliament delegation has arrived in Tehran, the first visit by U.K. lawmakers to Iran in years.

Iran's official news agency, IRNA, said Tuesday that the four-member delegation is headed by former Foreign Secretary Jack Straw.

Straw who last visited Iran in 2003 as Britain's top diplomat.

The British Embassy in Tehran was closed in late 2011 after hardliners overran the building. Iran also closed its embassy in London but relations have improved in recent months.

The visit by the British parliamentarians is the fourth by lawmakers from Europe since Iran's new president, moderate Hassan Rouhani, took office in August.

Rouhani has vowed a softer approach toward the West, which is at odds with Iran and suspects the country of seeking a nuclear bomb. Tehran denies the charge.