Iran's chief religious leader is urging Arab nations to boycott an upcoming U.S.-hosted peace conference.

Supreme Leader Ayatollah Ali Khamenei issued the call Saturday during a sermon in Tehran. 

The conference next month is aimed at resolving the issue of Palestinian statehood, but Ayatollah Khamenei says the real goal is to prop up Israel, which he called the "Zionist regime."

The cleric says previous peace conferences have been at the expense of the Palestinian people.  He questioned the need for Arab states to attend the forum, since the Palestinians themselves are not taking part. 

He did not mention talks between Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas, preparing for the conference.

In Saturday's sermon, the ayatollah also blamed the United States for the chaos in Iraq.

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