The five permanent U.N. Security Council members and Germany likely will consider restrictions on trade and arms for Iran when they meet Monday to discuss new ways to pressure Tehran to suspend parts of its nuclear program.
Senior representatives of the six nations were to meet at London's Foreign Office 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 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 who will be attending Monday's meeting said diplomats would examine options for further sanctions, including whittling away at lucrative export credits Iran receives from Europe in support of trade.
Restrictions on arms exports to Iran are also likely to be discussed, said the diplomat, who spoke on condition of anonymity because of the sensitivity of the subject.
"We are not applying pressure on Iran for pressure's sake," said the British diplomat. "We're applying pressure on Iran with the aim of getting them to address our concerns and to do that through negotiations."
The U.S. and its European allies have been urging Iran to halt its nascent enrichment program and re-enter negotiations meant to ease concerns that Tehran could be intending to use its civilian nuclear power program as a cover to produce weapons. Iran has refused to give up enrichment, and insists its only interest in the technology is for the production of fuel for nuclear power plants.
The British official said there was evidence that the Security Council's adoption of limited economic sanctions against Iran in December had begun to show success.
"We have a sense that the pressures that have been brought to bear so far are having an impact in Tehran. They are provoking a debate there," he said.
The December 23 resolution ordered all countries to stop supplying Iran 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's 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 worth of export credits to support trade with Iran and that some of those credits were already shrinking.
Meanwhile, Iranian President Mahmoud Ahmadinejad continued to sound a defiant tone. State-run radio quoted him as saying Sunday that Iran would press ahead with uranium enrichment. He also described his nation's path as a train with no brakes.
"The train of the Iranian nation is without brakes and a rear gear," he said. "We dismantled the rear gear and brakes of the train and threw them away sometime ago."
"The Westerners are not concerned about the existence and activity of ... centrifuges in Iran," he added. "They are concerned about the collapse of their hegemony and hollow power."
Secretary of State Condoleezza Rice responded by saying "they don't need a reverse gear. They need a stop button." She also told "Fox News Sunday" that Tehran needs "to stop enriching and reprocessing, and then we can sit down and talk about whatever is on Iran's mind."