Iranian parliamentary speaker Ali Larijani has urged Muslim leaders to support what he called Lebanese "resistance" of Western plots.
In a Wednesday speech, he reiterated other Iranian leaders' challenges to the legitimacy of the United Nations-backed special tribunal investigating the 2005 assassination of Lebanese prime minister Rafiq Hariri.
Larijani commented at a meeting of the Islamic Inter-Parliamentary Union in Abu Dhabi, where attendees had been expected to discuss the situations in Lebanon and the Palestinian territories.
Iranian state media say he also condemned the presence of foreign forces in countries including Iraq and Afghanistan and blamed Western nations and Israel for what he called the "assassinations" of several Iranian nuclear scientists.
Earlier, Tehran had called the meeting in the UAE "illegal" and said it would not attend. Iranian media reports said the UAE had originally called the meeting to resolve border disputes among Islamic states. The Fars news agency said Iran did not want to discuss three disputed Iranian islands.
The reports say Iran agreed to attend after the UAE said it would drop plans to discuss the issue.