Palestine issue remains top priority of the Islamc world. (Reuters Photo)

TEHRAN, Jan. 16 (Xinhua) -- Iran's President Hassan Rouhani said Tuesday that Palestine remains as the most important issue for the Islamic world, Press TV reported.

After the collapse of the Islamic State (IS) terror group in Iraq and Syria, the issue of Palestine has regained its importance for the Muslims, Rouhani said in the opening ceremony of the 13th Session of the Parliamentary Union of the Organization of Islamic Cooperation (OIC) in Iran's capital Tehran.

The current instability and insecurity gripping the region stem from continued Israeli occupation of the Palestinian territories, he was quoted as saying.

Rouhani urged the Islamic states to unite for the creation of a "calm region and peaceful foreign relations," adding that Iran views no country as its "competitor" in the region.

"Some countries, however, are following the wrong path and seek to widen the rifts among Muslim nations under the U.S. and Israel's influence," Rouhani said.

Rouhani criticized some Muslim states for what called their dependence on foreign powers, saying "the experiences of modern history teach us that these powers solely think about their own interests."

Iran believes it could even engage in negotiations and cooperation with the countries with which it has differences of opinion based on mutual respect, he added.

The ongoing Parliamentary Union of the Organization of Islamic Cooperation meeting, which will last until Wednesday, is attended by parliament speakers, deputy parliament speakers, and parliamentary delegations from 44 countries.