The US military on Thursday denied that any of its ships have visited Sudan, after Khartoum's foreign minister suggested the navy had made a brief port call.

"No US Navy ships have stopped at Port Sudan," the US Africa Command public affairs office said in response to a query from AFP.

On Tuesday, Foreign Minister Ali Karti told reporters: "Last month an American ship visited Port Sudan for a few hours".

He gave no further details but was speaking in the context of foreign warships visiting the country.

Karti said the navies of any country are welcome, "except Israel."

Official media, quoting Sudan's military, said Iranian warships which had been expected to visit Port Sudan on November 30 are now expected to arrive for a port call on Friday.

Two naval vessels from Iran spent about two days at the Red Sea port late last month.

Israeli officials have expressed concern about arms smuggling through Sudan and have long accused Khartoum of serving as a base of support for militants from the Palestinian Islamist movement Hamas which rules the Gaza Strip.

Khartoum wants Washington to end economic sanctions that were first imposed in 1997 over Sudan's alleged support for international terrorism, efforts to destabilise neighbouring governments and human rights violations.