Iran says it will not hand over its enriched uranium to the United States, insisting it is intended for peaceful use in sectors such as healthcare and electricity generation.

Iran's Ambassador to Namibia, Mohammad Beigi, speaking to NBC News, said Tehran will maintain its position ahead of a second round of talks.

"We are thinking that this step is against our national interests. Of course, we have to use this enrichment just for peaceful usage. That's very important. For example, these days, some Iranian factories are producing medicine using nuclear material."

Without it, he said it would be very difficult to "manage certain illnesses and support patients, especially those with cancer and other conditions. Iranian companies are currently producing these products. We already have more than 15 reports from the IAEA confirming that Iran has followed the peaceful use of nuclear energy." 

Ambassador Beigi also set out Iran's broader stance on the extended ceasefire, saying Tehran supports peace while reserving what it calls the right to defend its national interests under international law.

Iran views the United States' military deployment in the Middle East as undermining the ceasefire and violating international law, which Washington has consistently rejected.

"The Islamic Republic of Iran has always emphasised the establishment of just and lasting peace and has never been the initiator of tensions. Our position is based on principles, including the 10 points that the American side accepted before the first round of the ceasefire," he said.

He continued that "We have the right to legitimate defence under the UN Charter. We maintain this position as long as the United States continues what we consider violations of international law, including the blockade and seizure of Iranian ports and ships. Such actions are, in legal terms, equivalent to aggression."

Talks between Iranian and U.S. officials are expected to resume in the coming days, as both sides continue to trade blame over the breakdown of the first round of negotiations.