Restrictions on trade and arms for Iran were likely to be considered by the five permanent U.N. Security Council members and Germany, as the world powers on Monday sought new ways to pressure the country to suspend parts of its nuclear program.
Senior representatives of the six nations were in London to discuss how to respond to Iran's failure to respect a U.N. deadline to halt its uranium enrichment work.
The U.N.'s nuclear watchdog, the International Atomic Energy Agency, confirmed Thursday that Iran had ignored a Security Council ultimatum to freeze enrichment — a possible pathway to nuclear arms — and had instead expanded its program.
A senior British diplomat attending Monday's meeting at the Foreign Office said the representatives would examine options for further sanctions, including whittling away at export credits made available to companies that trade with Iran. Restrictions on arms exports to Iran also are likely to be discussed, said the diplomat, who spoke on condition of anonymity because of the sensitivity of the subject.
In Washington, State Department spokesman Sean McCormack said any futher actions would likely be incremental: "This is designed to proportionally increase pressure on Tehran."
McCormack said limited economic sanctions against Iran implemented in December had produced surprising results. "It started a very public discussion in Iran about the wisdom of their current course of defying the international system," he said.
After the meeting, the diplomats will return to their home capitals to report on their discussions.
The U.S. and its European allies have been urging Iran to halt enrichment and re-enter negotiations meant to ease concerns that the country could be intending to use its civilian nuclear power program as a cover to produce weapons. Iran insists its only interest in the technology is for the production of fuel for nuclear power plants.
In Russia, President Vladimir Putin and his foreign minister expressed concern Monday about talk of potential U.S. strikes against Iran in a televised exchange that underscored their demands for a negotiated solution.
"On the one hand, the Iranian leadership has not yet given satisfactory answers to well-known questions" posed by the IAEA, which is trying to determine whether Iran may be seeking to develop nuclear weapons, Foreign Minister Sergey Lavrov told Putin during a Cabinet meeting.
"On the other hand, prognoses and predictions that strikes will be conducted against Iran have become more common, and this causes concern," Lavrov said, adding that Vice President Dick Cheney "allowed such a possibility in recent comments."
Cheney said last week that the United States believes "it would be a serious mistake if a nation such as Iran became a nuclear power," and reaffirmed the Bush administration's policy that "all options are on the table" to deter Iran.
Putin, from offscreen in state TV video of the exchange at the meeting, asked Lavrov: "What kind of strikes are we talking about — without U.N. Security Council sanctions?"
Prime Minister Tony Blair's official spokesman said the IAEA report caused concern and that the London talks were aimed at gathering opinions on how to proceed.
"What Iran shouldn't in any way do is make any mistake about the unity of the international community in opposition to its continuing flaunting of what the U.N. has said its obligations are," said Blair's spokesman, who spoke on condition of anonymity in line with government rules.
The Dec. 23 Security Council resolution against Iran ordered all countries to stop supplying the country with materials and technology that could contribute to its nuclear and missile programs and to freeze assets of 10 key Iranian companies and 12 individuals related to those programs.
Besides a wider arms embargo and new economic penalties, other diplomats said last week that new, tougher measures could include a mandatory travel ban against individuals on the U.N. list and an expansion of the list to make more individuals and companies subject to sanctions.
Russia and China, which both have strong commercial ties to Tehran, forced other council nations — the U.S., Britain and France — to drop a travel ban and other tougher measures from the December resolution and it is likely they will resist some of the harsher restrictions this time around as well.
Still, the British diplomat said all participants in the talks supported an incremental tightening of sanctions.
On the possibility of economic penalties, he noted that European agencies provide $20 billion in export credits to support trade with Iran and that some of those credits were already shrinking.
Outside the Foreign Office, near Parliament, a small group of demonstrators chanted slogans denouncing Iranian President Mahmoud Ahmadinejad.
On Sunday, Iranian state-run radio quoted Ahmadinejadas as saying that Iran would press ahead with uranium enrichment, describing Tehran's path as a train without brakes.
Iran has said it plans to build as many as 20 nuclear reactors, part of a project to generate 20,000 megawatts of electricity through nuclear power within the next two decades.