Iran's president said on Wednesday that Britain will face "repercussions" over the seizure of an Iranian supertanker last week that authorities in Gibraltar suspect was breaching European sanctions on oil shipments to Syria.
"We have nothing to hide", he said after the IAEA meeting ended without any action taken against Iran.
Last month Trump said he had called off a retaliatory military strike against Iran at the last minute after Tehran shot down a United States drone that it said had crossed into its airspace, a claim denied by Washington.
The United Nations' nuclear watchdog is holding an emergency meeting on Iran on July 10, just days after Tehran announced its second violation of a 2015 nuclear deal it concluded with world powers.
The U.S. pulled out of the 2015 nuclear deal unilaterally past year and re-imposed crippling sanctions.
Low-enriched uranium, which typically has a 3-5% concentration, can be used to produce fuel for commercial nuclear power plants.
Iran says it is reacting to harsh United States economic sanctions imposed on Tehran since Trump pulled out of world powers' 2015 nuclear accord with the Islamic Republic previous year, and says all its steps were reversible if Washington returned to the deal.
"The latest steps indicate that Tehran's leadership has made a decision to move onto the offensive to create leverage vis-à-vis the worldwide community and bring about a solution to its constraints", a Western intelligence source told Reuters.
Enriched uranium at the 3.67% level is enough for peaceful pursuits but is far below weapons-grade levels of 90%.
In recent weeks, Iran has begun to openly breach limits on uranium enrichment set by the deal in order to pressure European signatories to salvage it. Iran has repeatedly denied any intent to develop atomic bombs.
It would reverse the major achievements of the agreement, meant to block Iran from making a nuclear weapon, and raise serious questions about whether the accord is still viable. Iran has conditioned any talks on first being able to export as much oil as it did before the USA withdrawal.
Tensions between Washington and Tehran have escalated, culminating in a plan for USA air strikes on Iran last month that Trump called off at the last minute.
The global atomic energy agency confirmed on Monday Iran had broken the 3.67 per cent threshold, passing 4.5 per cent, but the head of Iran's Revolutionary Guards insisted the world knew Tehran was not pursuing nuclear arms.
Washington is set on isolating Iran to force it to negotiate stricter limits on its nuclear program and, for the first time, to address calls to curb its ballistic missile program and its role around the conflict-ridden Middle East. That has been a political nonstarter in Washington, meaning that the prospect of negotiations between Washington and Tehran remains bleak.
But Trump's withdrawal from the deal on May 8, 2018 - and subsequent sanctions - have deprived Iran of the economic benefits it expected and dealt an additional blow on its economy.
France and other countries have called on Iran to go back to complying with the nuclear deal.