Iran has still not fulfilled all its promises to allow inspections of its nuclear sites, Jack Straw has said.
Jack Straw met Iranian President Mohammed Khatami
The foreign secretary was speaking as he met Iranian President Mohammed Khatami at the World Economic Forum in the Swiss ski resort of Davos.
Iran had promised to open up its nuclear sites last year, Mr Straw said.
Speaking later to politicians and business leaders, Mr Khatami insisted his country had never sought to develop weapons of mass destruction.
BBC correspondent Jonathan Charles, in Davos, said Mr Straw had told him Tehran had delivered on several of the promises it had made, but there were still some outstanding issues to be resolved.
On Wednesday, the first day of the forum, the foreign secretary commented on Iran's neighbour, Iraq, insisting that the US-led coalition would not dictate the future composition of any future government there.
The coalition rather intended to promote a "stable, internationally recognised federal government", he said.
The coalition is due to hand over power to the Iraqis by July.
"Our job is not to dictate Iraq's future, but to support the consensus of Iraqi opinion," said Mr Straw.
'Long way to go'
He said the new Iraqi government should reflect the diversity of its people and protect "the rule of law and human rights".
But he admitted: "We still have a long way to go".
"The security situation is of course my one concern and there have been difficulties in other areas too, such as reconstruction - perhaps more than some expected," he said.
Some 45,000 police were now on duty, with more being trained. About 17,000 reconstruction projects had been launched, 2,000 schools refurbished, 70m revised textbooks printed and distributed and more than 30m doses of vaccines had been provided since the summer.
Mr Straw conceded that the provision of services had not yet met "the expectations of the Iraqi people".