Russia's President Vladimir Putin, Iran's President Hassan Rouhani and Azerbaijan's President Ilham Aliyev pose for a picture during a meeting in Tehran, Iran November 1, 2017. (Reuters Photo)

TEHRAN, Nov. 1 (Xinhua) -- Russian President Putin said in Tehran Wednesday that the nuclear agreement between Iran and the world powers in 2015 is a "good pact in line with expansion of peace and stability in the region."

The Russian President Vladimir Putin was visiting Iran to attend the tripartite summit of Iran, Russia and Azerbaijan.

Iran's President Rouhani said Wednesday that his administration welcomes the participation of Russian investors and private sectors in joining Iran infra-structural projects, semi-official Mehr news agency reported.

Iran's industry and energy, rail networks, and the "North-South Corridor," extending from Russia through Azerbaijan to Iran, are the areas for cooperating between Tehran and Moscow, Rouhani said.

"So far, good agreements have reached between Iran and Russia in the areas of energy, peaceful nuclear technology, and transportation, but more efforts are needed to put these agreements into practice in the course of growing ties," he said.

"Cooperation of Iran and Russia has been of great influence in the war against terrorism in the region," Rouhani said, adding that this cooperation and exchange of views is still of importance at the closing stages of war on terror in Syria.

"The Islamic Republic of Iran holds that any instability in the region is harmful for all countries of the region," he added.

Therefore, Iran and Russia cooperation "has proved to the world that political settlement and security should be reinforced in Syria," he stressed.

Putin said that bilateral cooperation of Iran and Russia in energy, peaceful nuclear technology, railroad and transportation is developing and voiced Russia companies' readiness for joining project in Iran.

"Russia bears no limit in developing comprehensive ties with Iran and welcomes the growing trend of cooperation," he stressed.

"The tripartite meeting of presidents of Iran, Russia, and Azerbaijan can play a key role in developing transportation and transit, particularly in the North-South Transit Corridor," said Putin.

"Trade transactions between the two countries witnessed a jumping growth in 2016, and this trend should be maintained and accelerated," he said.