Iran's First Vice President Mohammad-Reza Rahimi called on Sunday for closer ties between Iran and Iraq.

In a meeting with visiting Iraqi Prime Minister Nouri al-Maliki in Tehran, Rahimi expressed hope that Maliki's trip to Iran would open a new chapter in the two countries' relations, the local satellite Press TV reported.

Relations between the Iranian and Iraqi nations and governments are unique and unbreakable, he was quoted as saying.

"At present, the economic and cultural exchanges between the two countries continue at a high level and we hope the continuation of this trend will remove any obstacle and problem in the way of the further development of Tehran-Baghdad relations in the shortest possible time," Rahimi added.

Stressing the necessity of connecting the two countries' railroads, Rahimi said that cooperation between Iran and Iraq in the fields of oil and transit will help to promote cooperation in other economic areas.

In the previous Iranian calendar year that ended on March 19, the value of bilateral economic ties between Iran and Iraq reached 9.7 billion U.S. dollars, which showed a 50-percent increase in comparison to the figures in the year before, the official IRNA news agency reported on Sunday.

It is expected that the trade value of the two neighboring countries will hit 12 billion dollars in the current Iranian year, said IRNA.

"If the two countries become united in an all-out manner, they will become a big power in the world," Rahimi said, according to Press TV.

For his part, the Iraqi premier called for the implementation of previous agreements and more collaboration between Tehran and Baghdad in such fields as energy, oil, infrastructure and commerce.

Maliki arrived in Tehran on Sunday for a two-day official visit. Accompanied by a high-ranking delegation, he is expected to meet with senior Iranian officials to discuss bilateral as well as regional issues.

The Iraqi prime minister is also expected to hold talks with Iranian officials about the next round of nuclear talks between Tehran and six world powers -- Britain, China, France, Germany, Russia and the United States -- to be held in the Iraqi capital of Baghdad on May 23.