Iran's Oil Minister Bijan Zanganeh has started negotiations with the visiting British Foreign Secretary Philip Hammond in the Iranian capital.
Hammond arrived in Tehran earlier on Sunday to reopen the UK embassy and hold talks with high-ranking Iranian officials.
During his two-day trip, in addition to Iran's oil minister, Hammond is scheduled to hold talks with Iranian President Hassan Rouhani, Foreign Minister Mohammad Javad Zarif, Parliament (Majlis) Speaker Ali Larijani and Governor of the Central Bank of Iran Valiollah Seif.
The British foreign secretary is accompanied by a politico-economic delegation, including representatives of major British companies such as the Royal-Dutch Shell.
Before imposition of international sanctions against Iran, Shell took part in development of a number of Iranian oil fields, including the offshore Soroush and Norouz fields.
According to Iranian media, the company owes Iran €2.3 billion, whose payment has been stalled as a result of sanctions on Iran's energy and financial sectors.
Iran, for its part, cooperated with Britain for the development of a gas field in the North Sea, but due to sanctions, the Islamic Republic has not been able to take advantage of the benefits of its cooperation so far.
Recent conclusion of a nuclear agreement between Iran and the P5+1 group of countries – the US, the UK, France, Germany, Russia and China – known as the Joint Comprehensive Plan of Action (JCPOA) has raised hopes about resumption of economic cooperation between Iran and other countries.
Under the JCPOA, limits will be put on Iran’s nuclear activities in exchange for, among other things, the removal of all economic and financial bans, against the Islamic Republic.
This is the first visit to Iran by a British foreign secretary since 2003.