WASHINGTON — US President Barack Obama is calling on UN nuclear inspectors to release data showing Iran is designing nuclear weapons technology in a bid to further isolate Tehran, a report said on Sunday.

The White House push for the release of International Atomic Energy Agency data comes after the United States accused Iran of sponsoring a plot to kill the Saudi ambassador to Washington, the New York Times reported.

Citing unnamed senior administration officials, the newspaper said the nuclear data did not "definitively point to the construction of a weapon" but would force the Iranians to provide answers about their nuclear program.

The United States and its allies including Israel have long accused the Islamic republic of developing nuclear weapons, but Iran insists its atomic programme is a peaceful one designed to fulfill the country's energy needs.

Tehran also has denied any involvement in the plot to kill the Saudi envoy.

The IAEA is planning to release details next month on what it suspects may be covert Iranian efforts to develop nuclear weapons, diplomats said in Vienna last week.

But the watchdog's chief, Yukiya Amano, is apparently concerned that Iran will throw UN inspectors out of the country if too much sensitive data is released, the Times reported.

The evidence reportedly would include details about work on technologies needed for designing and detonating a nuclear device, including how to turn uranium into bomb fuel, it said.

Iran says such documents have been fabricated.

The country is under four sets of UN sanctions for refusing for years to bow to international demands to rein in uranium enrichment.

Obama administration officials told the Times that they were mulling other ways to isolate Tehran, such as a ban on all financial transactions with the Central Bank of Iran and an expansion of a ban on the purchase of oil products.

"We are engaging in an effort to develop the multilateral support that would be critically important in having an action against the CBI really be effective," senior Treasury official David Cohen told lawmakers last week.

China and Russia however have been resistant to the idea of further sanctions, the Times said.

The idea of pushing for the release of IAEA data had been discussed before the plot against the Saudi ambassador was uncovered, but that news prompted the White House to "pursue a full-court, public press" on the issue, it said.