Mottaki said it should be up to Tehran to set the amounts to be exchanged, based on its needs.
A deal could represent a major breakthrough in the long-running dispute over Iran's nuclear programme, but it was not clear whether Iran's conditions would be acceptable to the United States and others.
Nuclear bomb fears
The uranium swap deal was first discussed last year between Iran and six world powers, which saw it as a way to ensure Tehran did not further enrich its uranium to a level that would be potentially usable in a nuclear bomb.
But Tehran, which insists its nuclear programme has only peaceful intentions, had
failed to respond positively to the proposal from the group - the US, Russia, China, Britain, France and Germany - until this week.
"[The] Islamic republic of Iran has shown it is serious about doing this, and we have shown it at the highest level."
Manouchehr Mottaki, Iranian foreign minister
Mottaki said he would discuss the exchange on Saturday with Yukiya Amano, the new head of the International Atomic Energy Agency, on the fringes of the Munich conference.
"We think all parties have shown their political will to fulfil this exchange," he said, without naming specific countries.
He added that the "Islamic republic of Iran has shown it is serious about doing this, and we have shown it at the highest level," referring to Mahmoud Ahmadinejad, the president.
Ahmadinejad said in a television interview on Tuesday that Tehran would have "no problem" sending abroad its stocks of low-enriched uranium to be further purified into fuel.
Iran needs nuclear fuel to power a UN-monitored research reactor in Tehran, but Western powers fear its uranium enrichment programme masks efforts to produce atomic weapons.
To curb such fears, the International Atomic Energy Agency has proposed that Tehran ship uranium to Russia and France to be further purified into reactor fuel.
Tehran agreed in principle to the offer during talks with world powers in October, but later appeared to reject the deal and said it preferred a gradual swap for fuel, preferably on Iranian soil.