US Secretary of State Condoleezza Rice has attacked the head of the UN nuclear watchdog for urging caution in the dispute over Iran's nuclear programme.
Mr ElBaradei won the 2005 Nobel peace prize for his work at the IAEA
She said diplomacy was best left to diplomats, not a technical body such as the International Atomic Energy Agency.
The criticism came after IAEA chief Mohamed ElBaradei said force should be a last resort in the Iran dispute.
He dismissed talk of military action in Iran as "hype" and urged people not to forget the lessons of war in Iraq.
Diplomacy 'with teeth'
Ms Rice maintained that "all options" were on the table to resolve the stand-off over Iran's refusal to end its uranium-enrichment work.
The US was committed to a diplomatic resolution but diplomacy had to have "a set of teeth" and incentives to work, she said.
Ms Rice made the comments while travelling to Israel in another attempt to restart Middle East peace talks.
"The IAEA is not in the business of diplomacy. The IAEA is a technical agency that has a board of governors of which the United States is a member," she said.
She added: "It is not up to anybody to diminish or to begin to cut back on the obligations that the Iranians have been ordered to take."
Iran denies it is trying to acquire nuclear weapons, insisting it wants nuclear power to generate electricity for civilian use.
The US has not ruled out a military attack against Iran to prevent it from acquiring a nuclear weapon.
Mr ElBaradei won the 2005 Nobel peace prize for his work with the IAEA to prevent nuclear energy being used for military purposes.