Prime Minister Benjamin Netanyahu, when he meets Barack Obama on Monday, will present the US president with an intelligence report asserting that Iran has amassed enough enriched uranium to produce a nuclear weapon, according to Britain’s Sunday Times. Netanyahu on Saturday night flew out for a four-day visit to the United States, vowing to expose “the truth” in the wake of Iranian President Hasan Rouhani’s recent overtures to the United States.

The dossier also states that Iran is developing a nuclear detonator at the Parchin site and conducting ongoing tests of the Shahab-3 ballistic missile, while producing plutonium at another site, Arak, the report said. “Iran has been making considerable progress with its nuclear program since June, when Rouhani was elected,” according to a source that the Times said was privy to the content of the intelligence report.

Israeli media reports over the weekend quoted sources in the Israeli government as saying that Iran was only a few months away from possessing enough enriched uranium for a bomb, with one report going so far as to state that Tehran had already produced at least one such weapon.

Israel is concerned over the thaw in Western-Iranian ties that has been developing at breathtaking pace in the last few days and culminated Friday with a phone call between the American and Iranian presidents.

“I am going there to represent the interests of the people of Israel, our readiness to defend ourselves and our hope for peace,” Netanyahu told reporters on the plane before taking off for the US. “I will say the truth. In the face of the sweet talk and the smiles one needs to tell the truth. Only the truth, today, is vital to the security of the world, and of course essential to the security of our country.”

Netanyahu is scheduled to meet Obama at the White House on Monday. A day later, he will be the final world leader to address this year’s United Nations General Assembly in New York.

During his address to the General Assembly in 2012, Netanyahu famously produced a cartoon diagram of a bomb and went on to elucidate his “red line” for Iran’s nuclear program: 90 percent of the amount of enriched uranium required to produce an atomic weapon. While beseeching Obama to present a “credible” military deterrent of his own, Netanyahu has threatened to order a strike on Iran’s nuclear facilities if Tehran threatened to cross that “red line.”

The prime minister has said he regards Iran’s recent outreach as a “smokescreen” designed to “fool” the West while the regime advances toward a nuclear weapons capability. He has set out conditions that he wants the international community to maintain before any lessening of economic sanctions.

Netanyahu’s meeting with Obama will mark the first time the two leaders have sat together since the American president’s March visit to Israel, and, more dramatically, since the historic phone call between Obama and his Iranian counterpart, Hassan Rouhani — the latest in a series of developments last week that signaled a warming of ties between the new nations. The last time a sitting US president spoke to a sitting Iranian president was before the Islamic Revolution in 1979.

Netanyahu issued no direct comment on the Obama-Rouhani conversation and instructed his ministers to remain mum. He intends to discuss Israel’s position on the Iranian president’s charm offensive – which included more benevolent rhetoric on ties with the US and the West, a stated willingness to compromise on transparency of the Iranian nuclear program and an acknowledgement that the Holocaust occurred – during his meetings with senior US officials. He will also make a public plea against easing the sanctions on the regime during his speech Tuesday at the General Assembly.

“Netanyahu understands that there is a lot of euphoria,” according to an unnamed senior Israeli official quoted by The New York Times. “Netanyahu knows that people in the international community will want to believe. I think you’ll see in his remarks a lot of facts, a lot of facts that no one denies.”