President George W. Bush, trying to keep pressure on Iran, called on Teheran Wednesday to "come clean" about the scope of its nuclear activities or else face diplomatic isolation. Meanwhile, Britain's Foreign Secretary David Miliband said the nation would press ahead with demands for tighter sanctions against Iran, despite a US intelligence report which claims Teheran has halted its pursuit of nuclear weapons. Bush demanded that Teheran detail its previous program to develop nuclear weapons "which the Iranian regime has yet to acknowledge." "The Iranians have a strategic choice to make," he said. "They can come clean with the international community about the scope of their nuclear activities, and fully accept the long-standing offer to suspend their enrichment program and come to the table and negotiate, or they can continue on a path of isolation." The US administration is worried that the new intelligence report weakens its leverage over Iran and its ability to build global pressure on Teheran to stop its uranium enrichment program. Bush, arriving in Nebraska on a campaign fundraising trip, said he had consulted with members of his national security team, who gave him a report about what Secretary of State Condoleezza Rice and National Security Adviser Stephen Hadley have learned in talks during the past several days with their counterparts in Britain, Germany, France and Russia. "These countries understand that the Iranian nuclear issue is a problem, and continues to be a problem and must be addressed," Bush said. Backing the US intelligence community, Bush said he appreciated its work in helping people to understand past and present activities in Iran and helping the administration develop a sound policy. "It is clear from the latest NIE that the Iranian government has more to explain about its nuclear intentions and past actions," Bush said. The British Foreign Secretary said Teheran was defying international demands to end uranium enrichment and should face a third UN resolution over its contested nuclear program. "The origins of that sanctions resolution are in the defiance by Iran of the international community in respect of uranium enrichment," Miliband said in a statement. "That defiance remains the case today." Miliband discussed the prospect of new sanctions with Chinese Foreign Minister Yang Jiechi during a meeting in London - part of which took place in a pod of the capital's giant London Eye Ferris wheel. But Yang declined to offer explicit backing for the British plan. "We hope that the Iran nuclear issue will get resolved appropriately through peaceful and diplomatic means," Yang said. Earlier, International Atomic Energy Agency director-general Mohamed ElBaradei said that Iran had been "somewhat vindicated" by the new intelligence review. ElBaradei called the report a "sigh of relief" because its conclusions also jibe with the agency's own findings. "Iran obviously has been somewhat vindicated in saying they have not been working on a weapons program, at least for the last few years," ElBaradei told reporters in Brazil's capital. He also said the release of the report signaled an opportunity for Teheran to prove it has no plans to develop a weapons program, and said Iranian authorities should seize the opportunity to prove that they have peaceful plans for nuclear energy. Iranian President Mahmoud Ahmadinejad has called the report was a "declaration of victory" for Iran's nuclear program.