"It is now time for the entire international community to step up and insist that Iran end its support for terrorists, including groups violently opposed to Israel and to the Middle East peace process," Powell said here late Sunday.

"Tehran must stop pursuing weapons of mass destruction and the means to deliver them," Powell told the annual policy conference of the American Israel Public Affairs Committee (AIPAC), a powerful Jewish lobby group.

Israeli Foreign Minister Silvan Shalom, who is scheduled to hold talks with Powell Monday, also attended.

Powell then singled out Syria, saying: "Syria now faces a critical choice.

"Syria can continue direct support for terrorist groups and the dying regime of Saddam Hussein, or it can embark on a different and more hopeful course," he said.

"Either way, Syria bears the responsibility for its choices, and for the consequences."

Powell said that as part of its "overall strategy in combating terrorism," Washington was "demanding more responsible behavior" from "states that do not follow acceptable patterns of behavior."

Washington considers both Syria and Iran state sponsors of terrorism.

Powell's warnings came two days after Defense Secretary Donald Rumsfeld on Friday told Iran and Syria not to interfere in the war on Iraq.

Rumsfeld accused Tehran of allowing hundreds of Iran-based fighters of Iraq's Shiite Muslim opposition to cross the Iraqi border in defiance of US calls for them to stay out.

And he said, "We have information of shipments of military supplies crossing the border from Syria into Iraq."

The deliveries, which included night vision goggles, "pose a direct threat to the lives of coalition forces," Rumsfeld said.

"We consider such trafficking as hostile acts and will hold the Syrian government accountable for such shipments."

He declined to say whether the Syrian government was behind the shipments, but stressed: "They control their border. We're hopeful that kind of thing does not happen again.

Iran and Syria denied the charges.

The warnings to Syria came after Syrian President Bashar al-Assad said he hoped US forces would fail to oust Iraqi leader Saddam Hussein and predicted that if they did, Washington and ally London would be confronted by a "popular resistance" that would prevent them from controlling the country.

The same day, Syrian mufti Sheikh Ahmad Kaftaro called for suicide attacks against US forces. And on Sunday, Al-Jazeera television reported that an unknown number of Syrians had arrived in Iraq's northern city of Mosul to fight for Saddam.

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