WASHINGTON (AFP) - The White House said Tuesday that Iraqi authorities were investigating the kidnapping of an Iranian diplomat in Baghdad, and reiterated support of treaties protecting foreign emissaries.

White House spokesman Tony Snow did not confirm the details of Sunday's abduction, allegedly carried out by men wearing Iraqi military uniforms.

"All we know is that the Iraqi government is investigating it and obviously we abide by and support the Vienna convention for the diplomats, but we don't really know a lot about it at this point," he said.

Snow said he was only aware of media reports about the kidnapping and therefore unable to confirm anything related to the case.

Iran on Tuesday held the United States responsible for Sunday's kidnapping.

"Jalal Sharafi, the second secretary at the embassy in Baghdad, was abducted on Sunday by a group linked to the defense ministry, which operates under the supervision of U.S. forces in Iraq," Iranian Foreign Ministry spokesman Mohammad Ali Hosseini said in Tehran.

Iran on Tuesday summoned the ambassadors of Iraq and of Switzerland, which represents U.S. interests in the Islamic republic.

Swiss ambassador Philippe Welti and Iraqi ambassador Mohammed Majid al-Sheikh were summoned to meetings with their respective regional directors at the Foreign Ministry.

"The kidnapping was contrary to international laws and the diplomat should be released at once and those who committed the terrorist act punished," the Iranian Foreign Ministry told the envoys.