The United States is hosting a high-level diplomatic meeting in Washington Friday to discuss the possibility of imposing new U.N. sanctions against Iran over its alleged nuclear weapons program.

Diplomats from the United States, Britain, France, Russia, China and Germany will participate in the meeting, which the U.S. hopes will lay the groundwork for a new U.N. resolution to toughen sanctions on Iran.

Zalmay Khalilzad, the U.S. ambassador to the United Nations, says Washington expects the issue to move to the U.N. Security Council for final approval within the next several weeks.

The U.N. imposed various sanctions on Iran last December and in March of this year for its refusal to stop enriching uranium. Highly enriched uranium can be used to build an atomic weapon.

Russia and Germany are opposed to any new sanctions.

Russia's U.N. ambassador, Vitaly Churkin, says any new punitive measures could increase tensions, and not resolve what he calls an "extraordinarily complex problem."

President Bush told reporters Thursday that the international community must keep the pressure on Iran to give up its alleged nuclear weapons program. He says the objective is to solve the issue peacefully - but insists Tehran must understand that the world will not allow it to gain the knowledge of how to build a nuclear weapon.

Mr. Bush says it is important to take seriously the threats from Iran, including remarks about using force against Israel.

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