In a letter submitted to the world's top diplomatic body on Tuesday, Tehran questions the "intent" of Washington's new nuclear policy and says it contains threats of nuclear attack against Iran, IRNA said.
"UN members should not tolerate or ignore such nuclear blackmail in the 21st century," says the letter, delivered by Iran's envoy to the UN Mohammad Khazai.
"The United States, in an illegitimate manner, has identified a non-nuclear country as a target of its atomic weapons and is drawing its military plans on this basis," the letter says, according to IRNA.
Last week Washington unveiled its reviewed nuclear policy which limits its use of nuclear arsenal but singles out Iran and North Korea as exceptions reportedly for flouting UN Security Council resolutions.
Obama himself in an interview with New York Times said Iran and North Korea were "outliers" when it came to his new nuclear policy.
"Such comments are not just expressing an intent, but are part of official documents which formulate the US policy in using atomic weapons against a non-nuclear country which is a NPT (Non-Proliferation Treaty) member," the letter says.
"And so it is a real threat to international peace and security and is also harming the NPT."
IRNA said the letter also says US officials such as Defence Secretary Robert Gates and Secretary of State Hillary Clinton have made "implicit threats" in public of "using nuclear weapons against Iran based on completely wrong assumptions."
It says Iran itself has been a victim of weapons of mass destruction in the past and is committed to creating a world without nuclear arsenals.
"UN members should take a firm measure to destroy all nuclear weapons as it is the only guarantee against their use or threats of using them," it says.
After a year of offering diplomatic initiatives towards Iran, Obama in recent weeks has stepped up global efforts to impose a fourth round of UN sanctions against Tehran for pursuing its nuclear programme.
Western countries want Iran to abandon the programme as they claim it is masking a weapons drive, a charge strongly denied by the Islamic republic.
On Tuesday, Obama said he was not interested in "having a long drawn-out process for months" and appealed to world powers to "move forward boldly and quickly" in sanctioning Iran.
