Iran won't be allowed to reach nuclear weapons' capabilities, U.S. President Barak Obama said in a statement on Thursday, adding that Iran was isolated in the international community as a result of American efforts.

Earlier Thursday, Iran claimed to have evidence of covert U.S. efforts against it, displaying what it said was a downed U.S. surveillance drone on official Iranian television.

"Military experts are well aware how precious the technological information of this drone is," the Fars news agency quoted a chief Iranian military officer as saying.

Addressing American efforts against Iran's reported attempts to achieve nuclear weapons capabilities, Obama reiterated later Thursday that "no options off the table means I’m considering all options" in regards to Iran, adding that Tehran has a choice if it wanted to end international sanctions and isolation.

Iran, Obama said, could either act "responsibly," and foreswearing the development of nuclear weapons, which would still allow them to pursue peaceful nuclear power, like every other country that's a member of the Non-Proliferation Treaty, or they can continue to operate in a fashion that isolates them from the entire world."

"And if they are pursuing nuclear weapons, then I have said very clearly, that is contrary to the national security interests of the United States; it's contrary to the national security interests of our allies, including Israel; and we are going to work with the world community to prevent that," the U.S. president said.

Obama also spoke of what he said were the lengths the U.S. had gone to ensure Iran would pay a price for its nuclear aspirations, saying that it was "very important to remember, particularly given some of the political noise out there, that this administration has systematically imposed the toughest sanctions on Iran ever."

"When we came into office, the world was divided, Iran was unified and moving aggressively on its own agenda," the American president said, adding: "Today, Iran is isolated, and the world is unified in applying the toughest sanctions that Iran has ever experienced. And it's having an impact inside of Iran. And that's as a consequence of the extraordinary work that's been done by our national security team."

Earlier Thursday, U.S. ambassador to Israel Dan Shapiro said that Washington has been fully cooperating with Israel when it comes to the Iran and its nuclear program.

"There is no issue that we coordinate more closely than on Iran," Shapiro said during a briefing to reporters in Tel Aviv.

Shapiro's comments come against the backdrop of uncertainty regarding the U.S.-Israeli coordination on a possible strike on Iran.

General Martin Dempsey, the chairman of the Joint Chiefs of Staff, said last month that he did not know whether Israel would alert the United States ahead of time if it decided to take military action against Iran.