The fragile ceasefire between Israel and Iran stood on Wednesday, with both sides claiming victory in the 12-day conflict despite uncertainty over the damage inflicted by US strikes on nuclear sites in Iran.

United States President Donald Trump, who helped negotiate the ceasefire, said on Wednesday that the truce was "going very well". Trump's special envoy to the Middle East, Steve Witkoff, said earlier that talks with Teheran were "promising" and that Washington was hopeful for a long-term peace deal.

In addition, Trump reiterated on Wednesday that US strikes resulted in the "total obliteration" of Iran's nuclear capabilities, setting the country's nuclear program back by "decades". His administration was countering an initial assessment report issued by the US Defense Intelligence Agency, which said the US B-2 bomber attacks on three key nuclear sites in Iran sealed off entrances to some facilities without destroying underground buildings.

Israeli Prime Minister Benjamin Netanyahu has touted what he described as a "historic victory", as the Israeli military said Iran's nuclear program was set back "by years". He said Israel had removed the "two immediate existential threats" and he was determined to thwart any attempt by Teheran to revive its weapons program.

Iranian President Masoud Pezeshkian said his country had gained a "great victory", and many local residents were celebrating. He said the aggressors failed in their goals of destroying Iran's infrastructure, obliterating its peaceful nuclear energy program and inciting social unrest.

In Teheran, Iranian lawmakers voted on Wednesday in favor of a plan for the government to suspend cooperation with the International Atomic Energy Agency, the United Nations' nuclear watchdog, Iranian state TV said. To take effect, the plan would require final approval by the Supreme National Security Council. Iran has said its enrichment activities are for civilian purposes only.

"The IAEA, which refused even to appear to condemn the attack on Iran's nuclear facilities, has put its international credibility up for sale," Iran's Parliament Speaker Mohammad Bagher Ghalibaf said.

Under the plan, IAEA inspectors would only be allowed to enter Iran with explicit approval from the Supreme National Security Council, and only if the agency guaranteed the security of the country's nuclear facilities, Iran's Nournews reported.

IAEA chief Rafael Grossi said on Wednesday that the UN watchdog's top priority is returning to Iran's nuclear facilities to assess the impact of recent military strikes on Teheran's nuclear program.

Amid growing concerns over potential radiation leaks in Iran following the bombings of three nuclear facilities, the IAEA released a statement on Tuesday in which it said that "some localized radioactive as well as chemical release" has been detected at the damaged sites, although Grossi said that "there has been no report of increased off-site radiation levels".

"During these attacks, we have seen extensive damage at several nuclear sites in Iran, including its uranium conversion and enrichment facilities," Grossi said. However, "there has been no radiological impact to the population or the environment in neighboring countries".

Mahdi Mohammadi, an adviser to Iran's parliament speaker, said Iran had moved its nuclear infrastructure from Fordow. An adviser to Supreme Leader Ayatollah Ali Khamenei was quoted by Iranian media as saying on Tuesday that Iran still had stocks of enriched uranium and "the game is not over".

Sina Azodi, director of the Middle East studies program at George Washington University, told Al Jazeera: "The Israelis have not been able to achieve their objectives in destroying the Iranian nuclear program or forcing Iran to capitulate. Netanyahu may have achieved and can claim some short-term victory, but in the long term, I don't think his leadership serves Israel's interests."

Since June 13, at least 610 Iranian civilians have been killed and more than 4,700 injured, while Iran's retaliatory attacks on Israel have claimed 28 lives, according to official figures.