U.S. plans to move its Israel embassy to Jerusalem are a sign of incompetence and failure, Iranian Supreme Leader Ayatollah Ali Khamenei said on Wednesday.
U.S. President Donald Trump is expected to announce that the United States recognises Jerusalem as the capital of Israel and will move its embassy there, breaking with longtime U.S. policy and potentially stirring unrest.
"That they claim they want to announce Quds as the capital of occupied Palestine is because of their incompetence and failure," Khamenei said, using the Arabic name for Jerusalem, according to his official website.
He made the remarks to a group of top Iranian officials, regional officials and religious figures attending a conference in Tehran.
Iran has long supported a number of Palestinian militant groups opposed to Israel.
"The issue of Palestine today is at the top of the political issues for Muslims and everyone is obligated to work and struggle for the freedom and salvation of the people of Palestine," Khamenei said.
At the same gathering, Iranian President Hassan Rouhani said, "Quds belongs to Islam, Muslims and the Palestinians, and there is no place for new adventurism by global oppressors," according to Mizan, the news site for the Iranian judiciary.
Iran wants "peace and stability" in the region but will not tolerate the violation of Islamic holy sites, Rouhani said.
"No Muslim population, including Iran, will tolerate the violation of oppressors and Zionists against Islamic holy sites," Rouhani said, according to Mizan.
The United States has not been able to reach its goals and seeks to destabilise the region, Khamenei said.
"On the issue of Palestine, (U.S.) hands are tied and they cannot advance their goals," Khamenei said, saying the Palestinian people would be victorious.
"American government officials have said themselves that we have to start a war in the region to protect the security of the Zionist regime (Israel)," Khamenei said.
Certain rulers in the region are "dancing to America's tune" Khamenei said, an indirect reference to Iran's main regional rival Saudi Arabia.
"Whatever America wants, they'll work against Islam to accomplish it," he said.