US Secretary of State Condoleezza Rice will host her counterparts from Britain, China, France, Germany and Russia as well European Union foreign policy chief Javier Solana at a working dinner.
The informal meeting will focus on Tehran's rejection of repeated UN demands that it halt uranium enrichment.
It will coincide with continuing bargaining in the 15-member UN Security Council on a Franco-British draft resolution that would legally require Iran to freeze all uranium enrichment and reprocessing activities.
US Ambassador to the UN John Bolton said that the ministers would "talk about the longer-term policy that we need to pursue to stop Iran from achieving a nuclear weapons capability".
Claim and counter claim
Western powers suspect Iran is using its civilian atomic program to hide efforts to develop nuclear weapons. But Iran insists that its aims are peaceful and claims it has the right to pursue uranium enrichment as a signatory to the nuclear Non-Proliferation Treaty.
Russia and China adamantly oppose sanctions and the use of force against Iran, their key trading partner. They have veto power as permanent members of the Security Council along with Britain, France and the United States.
Russian Deputy Foreign Minister Sergei Kislyak said Saturday the
Franco-British draft, which is backed by the United States and Germany, "requires major changes".
Moscow and Beijing object to the draft's reference to Chapter Seven of the UN charter and its suggestion that the Iranian nuclear program constitutes a threat to international peace and security.
Chapter Seven can authorise economic sanctions or military action as a last resort.
The proposed draft would oblige Iran to suspend uranium enrichment, the process creating fuel for nuclear reactors and -- potentially -- the core of an atomic bomb. It warns, in case of Iranian non-compliance, of unspecified "further measures" requiring another resolution.
It needs at least nine votes and no veto from any of the council's permanent members. But Iran remains defiant against calls for it to stop enriching uranium.
Iran’s refusal
Iran has again said that it would refuse to comply with any UN Security Council demand to halt its nuclear program and warned the crisis was heading toward a "confrontation".
"We will not accept any resolution that is against our rights," said
Iranian foreign ministry spokesman Hamid Reza Asefi, adding that "a suspension and pause (of enrichment) is not on the agenda at all."
Ahead of Monday's high-level meeting, Ms Rice telephoned her Russian counterpart, Sergei Lavrov. Diplomats said Ms Rice would use Monday's dinner to try to reassure her Russian and Chinese colleagues about US intentions.
While insisting that it wants a diplomatic solution to the standoff with
Tehran, Washington has pointedly not ruled out military action to prevent Iran from acquiring nuclear weapons.
Russia and China say the nuclear standoff can only be resolved diplomatically, with the International Atomic Energy Agency (IAEA) leading the process.