Diplomats from the ECO's member states -- Iran, Pakistan, Turkey, the five countries of Central Asia, Azerbaijan, and Afghanistan -- will ostensibly meet to discuss economic cooperation. On the agenda are the procedures for business visas and a proposed train link between Istanbul and Almaty.
But the ECO's ninth annual summit is likely to be overshadowed by the Iranian nuclear crisis and the presence of Iranian President Mahmud Ahmadinejad.
Azerbaijan's presidential office told the French news agency AFP that Ahmadinejad was planning to hold presummit talks with the leaders of Afghanistan, Azerbaijan, Pakistan, and Turkey on May 4. Iranian Nuclear Standoff
Iran has already taken the spotlight. On the sidelines of the talks, Iranian Foreign Minister Manuchehr Mottaki warned that taking Iran's nuclear dossier to the UN Security Council "is a political decision and the technical issue of nuclear energy should not be politicized by some specific countries."
The Security Council is currently discussing a draft resolution introduced by permanent members Britain and France. The draft resolution calls on Iran to suspend uranium enrichment or possibly face further action, which could include sanctions.
The United States and other Western countries are concerned that Iran is trying to develop nuclear capabilities. Iran insists its nuclear program is only for peaceful purposes.
Azerbaijani Foreign Minister Elmar Mammadyarov said on May 4 that Baku supports Iran's efforts to pursue a peaceful nuclear program and objects to use of force in settling the crisis. Azerbaijani Balancing Act
Relations between Iran and Azerbaijan have lately intensified.
While in Baku in mid-April, Iranian Defense Minister Mostafa Mohammad-Najjar said he hoped Azerbaijan would explain Iran's position to the United States. Mohammad-Najjar also praised Azerbaijan as Iran's "best regional ally."
A week later, President Ilham Aliyev traveled to Washington, where he met with senior U.S. officials, including President George W. Bush. Aside from discussions about the energy flow from the Caspian region and democratic reforms, the two presidents also discussed Iran.
Before Aliyev's trip, some analysts in Azerbaijan had speculated that Bush would attempt to solicit Azerbaijan's support, in the event Washington decides to use force against Tehran.
But Aliyev was resolute. Speaking on April 26, he said that if the United States decided to attack Iran, it would have to do so without Azerbaijan's help as the two countries have a nonaggression treaty.
Aliyev did, however, emphasize in Washington that Azerbaijan remains a strategic partner of the United States. "We are allies in the war on terror," he said. "We have been from the very first day shoulder-to-shoulder with the United States in peacekeeping operations in various parts of the world, and we'll continue to contribute to the creation of peace and stability in the region."
That hasn't stopped speculation in the Azerbaijani press about Aliyev's true intentions.
The Azerbaijani opposition daily "Yeni Musavat" reported on May 2 that while in Washington Aliyev committed his country to playing a role in possible attacks on Iran. The report was based on a statement of an unnamed foreign diplomat.
Iran and Azerbaijan share a nearly 300-kilometer border and more than 20 percent of Iran's population is ethnic Azeri.
Visit RFE/RL's Azeri-language website, featuring news, analysis, features, streaming audio, and more in Azeri, courtesy of RFE/RL's Azerbaijani Service.
To view RFE/RL's archive of English-language articles on Azerbaijan, click here.