Iran says it will not hold direct talks with the United States on Iraq, despite calls by Iraqi political leaders for such a dialogue.

Iran Foreign Ministry spokesman Hamid Reza Asefi said Sunday such talks are not possible because of what he called Washington's unreasonable attitude.

Asefi did not specify what Tehran considered inappropriate behavior. But Iran has accused the United States of putting unfair pressure on Tehran over its nuclear program.

Iraqi Shi'ite leader Abdel Aziz al-Hakim said Saturday in Tehran that direct talks with the United States could benefit both Tehran and Baghdad.

The secretary of Iran's Supreme National Security Council, Ari Larijani, said in March that Tehran was willing to open talks with Washington to help resolve problems in Iraq.

But, U.S. National Security Advisor Stephen Hadley said Wednesday Iran was no longer interested in such talks.

He said U.S. diplomacy with Iran would focus on the nuclear issue.

Some information for this report was provided by AFP and Reuters.