"We have stated on several occasions and we say it again that we stand alongside the Lebanese army and we are prepared to cooperate with it," Iran's Defense Minister Ahmad Vahidi told Iranian television on the sideline of meetings with Lebanon's visiting Prime Minister Saad Hariri.
The remarks were made as the Iranian defense minister offered a gilded sub machine gun to Hariri after talks. The symbolic move was broadcast by Iranian television. The Tondar model gun is used in urban warfare.
The move came as U.S. lawmakers sounded heightened concern over the influence of Iran and Syria on militant Islamist groups in Lebanon, including Hezbollah.
"Hezbollah, with the help of Iran and Syria, is massively rearming, the Lebanese government is becoming more and more subordinate to Iran and Syria, and the line between the Lebanese armed forces and Hezbollah is gradually being erased," Rep. Ileana Ros-Lehtinen, the top Republican on the House Foreign Affairs Committee, said in a statement.
"We need to have a clear vision of what the end state is and how we can achieve it," she said, citing mounting concerns over what she alleged to be ill-fated diplomatic efforts by the United States and the United Nations to counter Hezbollah's growing might.
Last month the United States, trying to counter Iran's influence over Lebanon, lifted a freeze on $100 million in U.S. military aid to Lebanon.
But wooing its traditional partner, Iran this week criticized a U.N. tribunal probing the 2005 assassination of Hariri's father, former Premier Rafiq Hariri, while condemning his killers as "enemies of Lebanon."
The probe has suggested the indictment of Hezbollah members believe to have orchestrated the murder. Leaders of the Lebanese militant group have threatened retaliation.
The court is expected to announce its findings by the end of 2010.
Iran has long aided Lebanon's Shiite group Hezbollah, which however is spearheading opposition against the Hariri government on charges of leaning to the West.
A U.N. resolution in 2004 called for the disbanding and disarmament of all militias in Lebanon.
Iranian President Mahmoud Ahmadinejad visited Lebanon in October, signing more than 17 bilateral agreements, exclusively focusing on strengthening trade and military cooperation.
The visit was the first official trip by Hariri to Iran as Lebanon's prime minister.