Qatar Amiri Diwan shows Qatar s Emir Sheikh Tamim bin Hamad al-Thani welcoming Iranian President Ebrahim Raisi (L) upon his arrival to Qatar on February 21, 2022. AFP
Raisi and Qatar's emir, Sheikh Tamim bin Hamad al-Thani, a close US ally, are also expected to discuss growing efforts to revive a stalled international deal to regulate Iran's nuclear programme.
Tuesday's Gas Exporting Countries Forum will be overshadowed by growing tensions around Ukraine which have boosted demand for gas as well as the price paid by consumers.
Producing nations say they will not be able to provide substantial amounts of gas to Europe if Russia, which has been accused of preparing an attack on Ukraine, cuts supplies in any sanctions showdown.
Raisi has not travelled in the Gulf region since taking office in June, and it is only his fourth trip abroad. Qatar authorities imposed stringent security for his arrival at Doha airport, where he was met by the emir.
Qatar has added the Iran nuclear dispute to its list of diplomatic hotspots where it has taken a behind-the-scenes mediation role.
Earlier this month Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al-Thani went on an unannounced visit to Tehran after the emir met US President Joe Biden in Washington.
The Qatar government said that the emir and Raisi would discuss issues of "common concern" without giving details. Diplomats said, however, that the nuclear talks would be on the agenda.
In 2015, Iran and six world powers including the United States reached a landmark nuclear agreement that offered Tehran sanctions relief in exchange for curbs on its atomic programme.
The United States unilaterally withdrew from the deal in 2018 under then president Donald Trump and reimposed heavy economic sanctions.
Talks on reviving the deal known as the Joint Comprehensive Plan of Action (JCPOA), have been held in the Austrian capital Vienna since late November, involving Britain, China, France, Germany and Russia directly and the United States indirectly.
Raisi and the Qatari emir will be joined at Tuesday's summit by Algeria's President Abdelmadjid Tebboune and Trinidad and Tobago's Prime Minister Keith Rowley. Energy ministers from the other seven forum members who include Russia will also take part.
Ministers from the 11-member group were to meet later Monday to approve a summit statement that industry analysts predicted would touch on the lack of spare supplies that could help Europe, where consumers are already paying record prices for gas.
Qatar and other countries have insisted that massive investment is needed in gas, and that they need the certainty of long-term contracts to be able to guarantee supplies to Europe.
The European Union has long resisted the 10, 15 and 20-year contracts signed by other major customers for Qatar's gas, who include China, Japan and South Korea.
The United States has asked Qatar to help Europe by preparing emergency supplies if the Ukraine crisis erupts.