"We would like to make that payment ($2 billion) as soon as possible. As yet, we cannot do so," Reuters quoted Edward Daniels, Shell's executive vice-president for commercial and new business development, as saying on Monday.
“Clearly Iran remains under sanctions with time before sanctions will be unwound and clearly we will be absolutely adhering to all sanctions," Daniels added.
Shell has around $2 billion in outstanding debt to the Islamic Republic as a result of Iranian oil deliveries which Shell had been reportedly unable to pay for due to sanctions.
He added that the energy giant is seeking to invest in Iran’s huge energy sector.
"…when sanctions are removed we will look to examine possible options to work in Iran,” Daniels added.
"Iran is and will be an important potential business area but of course it will have to rank with other projects that we have across the world -- so yes it is a very large player in oil and gas reserves but projects need to make economic sense for our company," he further said.
Shell met Iranian Oil Minister Bijan Namdar Zangeneh and Central Bank Governor Valiollah Seif while on a British government visit to reopen the country's embassy in Tehran.
British Foreign Secretary Philip Hammond arrived in Tehran on Sunday to reopen the British embassy after a 4-year diplomatic breakdown between the two nations.
The thaw in Iran-Britain relations follows finalization of a landmark nuclear deal between Tehran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) on July 14.