Iran's foreign minister said a fresh round of talks with Washington would take place "soon", while insisting that enrichment was Tehran's "inalienable right" and building trust would take time.
Abbas Araghchi said the first round of talks in Oman on Friday had been a "good start".
"(Nuclear) Enrichment is our inalienable right and must continue. Even with bombing they could not destroy our capabilities," Araghchi said, according to excerpts published in Persian on his official Telegram channel of an interview with the Al Jazeera network.
"We are ready to reach a reassuring agreement on enrichment," he added during the interview, which was later released in parts by Al Jazeera with Arabic dubbing.
"The Iranian nuclear case will only be resolved through negotiations."
Araghchi's remarks came a day after renewed nuclear talks in Muscat with Washington, which has deployed an aircraft carrier group to the Middle East following Iran's deadly response to anti-government protests.
Friday's negotiations were the first since nuclear negotiations between Iran and the United States collapsed last year following Israel's unprecedented bombing campaign against Iran, which triggered a 12-day war.
During the war US warplanes bombed Iranian nuclear sites.
Araghchi called Friday's talks "a good start", but insisted that "there is a long way to go to build trust".
He warned that Iran "will attack their (US) bases in the region" if Washington targets Iranian territory.
He said the discussions in Muscat were "indirect", via Omani mediation, but said that there was "an opportunity" for a handshake with the US delegation.
The two sides had agreed to hold another round of talks "soon", but the date has yet to be determined, Araghchi said.
He said Iran's missile program was "never negotiable" because it relates to a "defense issue".
The United States has sought to address Iran's ballistic missile program and its support for militant groups in the region -- issues which Israel has pushed to include in the talks, according to media reports.
Tehran has repeatedly rejected expanding the scope of the negotiations beyond the nuclear issue.
Araghchi also criticized what he said was a "doctrine of domination" that allows Israel to expand its military arsenal while pressuring other countries in the region to disarm.
"Israel's expansionist project requires that neighboring countries be weakened: militarily, technologically, economically and socially," Araghchi said.
"Under this project Israel is free to expand its military arsenal without limits ... Yet other countries are demanded to disarm. Others are pressured to reduce defensive capacity. Others are punished for scientific progress," he added.
"This is a doctrine of domination."
