Iran''s nuclear program is of "critical concern" and will top the agenda when foreign ministers from the Group of Eight nations meet Monday to discuss global security, Canada''s foreign minister said.

Foreign Minister Lawrence Cannon said he''ll press for stiffer sanctions against Iran when G-8 ministers assemble in Gatineau, Quebec for the meeting which begins Monday evening and continues through Tuesday.

The United States and its Western allies have been pushing for a fourth round of U.N. sanctions against Iran over its nuclear program. Iran insists its nuclear program is for peaceful means only, but Western powers believe the country is working to produce an atomic weapon.

"Unfortunately I believe we are left with little choice but to pursue additional sanctions against Iran ideally through the United Nations Security Council," Cannon said.

Cannon said he''ll discuss with his G-8 colleagues what they can do to put additional pressure on Iran to persuade it to stop its nuclear enrichment activities and convince them to return to the negotiating table.