Mahmoud Ahmadinejad, in the northeastern city of Mashad, where newspapers said he would spend five days, said: "I will give you, the Iranian nation, good nuclear news during the time I am [here]."
His comments echoed remarks by other officials suggesting the imminent announcement of progress in Iran's nuclear programme, which the West fears is a cover to develop atomic weapons.
The daily Jomhuri-ye Eslami newpaper wrote: "It was said the good news is related to Iran's achievement of uranium enrichment at 3.5% and creating a laboratory platform that will register Iran in the club of nuclear fuel countries."
It gave no source or further details.
Uranium enriched to a low level can be used as fuel to generate electricity. Fuel for use in Iran's only nuclear plant now under construction would need to be enriched to 3.5%. Uranium must be enriched to far higher levels for bomb-making.
Iran has always insisted its enrichment of uranium is for civilian use only.