Canada will press the Group of Eight leading industrialized nations to tighten United Nations sanctions on Iran when it hosts a meeting of foreign ministers from the grouping on Monday and Tuesday.
International pressure is building on Tehran to halt its nuclear enrichment program, which Western nations say is aimed at developing the ability to build atomic weapons. Iran denies this, saying it needs nuclear energy to generate electricity.
Canadian Foreign Minister Lawrence Cannon said Iran would be of critical concern when G8 foreign ministers met in the Quebec town of Gatineau, across the river from the federal capital, Ottawa.
I will discuss with my G8 colleagues what we can do to put additional pressure on Iran to persuade it to stop its nuclear enrichment activities, he told reporters on Friday.
Unfortunately I believe we are left with little choice but to pursue additional sanctions against Iran, ideally through the United Nations Security Council.
The United States wants the council to impose a fourth round of sanctions against Iran but needs the agreement of China, which for months refused to discuss the idea.
Valerie Jarrett, a senior adviser to U.S. President Barack Obama, said on ABC's This Week program on Sunday that a U.S. agreement with Russia announced last week to reduce nuclear stockpiles was a sign of good cooperation that could lead to greater unity on Iran.
We're going to have a coalition that will really put pressure on Iran and try to stop them from doing what they're trying to do, she said.
She added: I think that we have a strong force in the making, and Iran will back down.
A senior Chinese official took part in a conference call with five other world powers last week to discuss more sanctions but no deal emerged. China, along with Russia, has close business ties with Iran.
Cannon said the G8 would also discuss North Korea, which is boycotting international talks designed to end Pyongyang's efforts to build nuclear weapons.
The United Nations imposed new sanctions last year after North Korea detonated a device in May.
I do think the sanctions are effective ... we will continue to enforce these sanctions aggressively until North Korea changes its course, said Crowley.
The G8 foreign ministers will start their meeting at 6 p.m. on Monday. They are due to end at around 2 p.m. on Tuesday.
(Additional reporting by Steve Holland in Washington)
(Editing by Doina Chiacu and Eric Beech)