KABUL (IRNA) -- United Nations special representative in Afghanistan Tom Koenigs said here on Thursday that the world political tension should not contaminate the favorable neighborly relations between Iran and Afghanistan.

Speaking to reporters, he said that he will visit Tehran in the current year to discuss further improvement of Iran-Afghanistan ties.

"In a meeting with Afghan President Hamid Karzai on the issue, I was asked to convey the Afghan people's message of peace, friendship and will for cooperation to the Iranian nation," he added.

Turning to the historical and religious commonalties as well as the common language of the two states and the fact that Iran is one of the best neighbors of Afghanistan, Koenigs urged Iran to invest in the Afghan market and enter into trade with it.

"Iran's nuclear program and the pressure by the international community on it can never affect its relations with Afghanistan. After the downfall of Taliban, all of its friendly neighboring states cooperated to promote peace and stability in this country, despite the discord among them," he said.

The UN envoy said that the neighboring countries should realize that they can hardly manage to establish tranquility and stability in Afghanistan, unless they collaborate with each other.

"Rather than accusing one another of interference in each other's internal affairs, they should attempt to reach accord through dialogue," he added.

Koenigs said that the growth of every of the neighboring states will directly have an impact on the other, adding that for instance, improvement of the economic situation in Iran accounts for the acceptable development in the neighboring Afghan city of Herat.

"The United Nations currently makes effort to raise the level of regional cooperation among Afghanistan's neighboring states and so far Iran, India and Pakistan have had the greatest share in the country's reconstruction," he added.

He referred to Iran and Afghanistan as two of the 191 UN member states and said that during his upcoming visit to Tehran, he will discuss with Iranian official the prospect of raising the level of ties between the two countries.

Koenigs visited Pakistan a while ago and he is scheduled to tour Afghanistan's neighboring countries to discuss the improvement of mutual relations.