Mutual trust among littoral states to the Caspian Sea is vital for a vibrant investment climate in the region's energy sector, the Azeri foreign minister said.

Azeri Foreign Minister Elmar Mammadyarov met with regional leaders in Moscow to discuss the importance of energy links in the Caspian region, which forms the foundation for some of the largest oil and natural gas pipeline networks in the world.

All of the nations that border the Caspian Sea have an obligation to ensure the right investment climate exists in the region, he said.

"Surely, the interests of the regional countries in improvement of investment climate, production of energy resources, establishment of security communications, as well as ensuring stability and security in the region require us to make additional efforts to reach agreement on all outstanding issues," he told the state-run Azeri Press Agency.

Littoral states to the Caspian Sea are at odds over territorial boundaries. Coastal states must first agree on the international laws defining it before settling the legal status of the area.

Mammadyarov said Tuesday the Azeri government puts cooperation with Caspian littoral states at the top of its agenda.