Robert Gates, the United States defence secretary, has said that the US has no plans to release five Iranians who were captured in Iraq and accused of supporting anti-government fighters there.
He also rejected speculation that the US had been part of a deal which led Iran to release 15 British servicemen earlier on Thursday.
"I think there's no inclination right now to let them go," Gates told reporters in Washington when asked about the five Iranians, who were captured by US forces in northern Iraq in January.
Washington has denied that it had been involved in any deal which offered concessions to Iran in return for the release of the 15 British servicemen, who were seized by Iranian troops near the southern Iraqi city of Basra.
George Bush, the US president, said on Tuesday that he agreed with Tony Blair, the British prime minister, "that there should be no quid pro quos when it comes to the hostages".
Access considered
Gates, however, said that US and Iraqi officials were considering arranging for Iranian representatives to visit the captured men, whom Iran says are legitimate diplomats.
"Iraqi government officials and US officials are discussing if there's some way, perhaps, that there could be some kind of Iranian access to them," he said.
"But as far as I know, there's no requirement for that.
"I don't think that consular access is being considered. I think the issue is whether there's some other means by which some other access might be given."
Gates's comments came after Major-General William Caldwell, a US military spokesman, told reporters in Baghdad that a consular request to visit the five Iranians was "being assessed".
The five Iranians were arrested by US forces in the northern city of Irbil, in Iraqi Kurdistan, on January 11.
US officials accused the men of being members of the elite Al-Quds brigade of Iran's Revolutionary Guards and of helping organise attacks on US and Iraqi forces.
Washington and Tehran broke off diplomatic ties almost 27 years ago and US interests in Iran are conducted via Switzerland.