WASHINGTON - US President Barack Obama on Monday ordered the freezing of Iran's property under US jurisdiction, including that of the country's central bank, as the US and its allies are pressing hard over the Islamic republic's controversial nuclear program.

Calling them "additional steps" against Iran, the president ordered "all property and interests in property of" the government of Iran as well as the republic's financial institutions under US jurisdiction, including the Central Bank of Iran, to be "blocked and may not be transferred, paid, exported, withdrawn, or otherwise dealt in."

The property of persons determined to have links to those already under US sanctions is ordered to be frozen as well.

In his executive order, Obama said the move aims in particular to counter the "deceptive practices" of Iran's central bank and other banks to conceal transactions of sanctioned parties, the deficiencies in Iran's anti-money laundering regime and the weaknesses in its implementation, and the "continuing and unacceptable" risk posed to the international financial system by Iran's activities.

Obama's order, which becomes effective at 12:01 am EST on Monday (1701GMT), came amid heightened tensions between Western countries and Iran over the latter's nuclear program and growing rumors about an imminent strike by Israel on Iran's nuclear facilities.

In an interview with the NBC television network on Sunday, Obama said the US will work with Israel to prevent Iran from becoming a nuclear power, and urged Iran to "stand down" on the current standoff.

When asked if Israel is determined to attack Iran, Obama said he didn't think that Israel has made such a decision. He emphasized his goal of resolving the standoff diplomatically, while reiterating that he was not taking any options off the table.

The US and its European allies have expanded their sanctions against Iran to target its oil exports, the lifeline of the country's economy, prompting threats by Iran to close the Strait of Hormuz, one of the world's most critical oil route.

The Washington Post, quoting US Defense Secretary Leon Panetta, reported last Thursday that Israel might strike Iran as early as this spring.

Iranian Supreme Leader Ayatollah Seyyed Ali Khamenei warned the next day against any war threats on Iran, saying "Threats of war is for the loss of the United States and the war itself is ten times for the loss of the United States."