The Iranian president has arrived in Lebanon for a two-day tour.
Israeli officials expressed fears that Mahmoud Ahmadinejad will give Tehran's Shia ally hizbollah a boost and use the opportunity to attack Israel.
The visit, Mr Ahmadinejad’s first since he was elected in 2005, has divided the country. Mr Ahmadinejad’s Iran is a powerful supporter of terror group Hizbollah, the main opponents of the pro-Western Lebanese government’s.
He was greeted by a crowd of thousands of cheering supporters, who threw sweets and rose petals at him. The streets leading to Beirut, the country’s capital, were lined with Hizbollah flags and giant posters of Mr Ahmadinejad.
He will be visiting villages near to the border between Israel and Lebanon, as well as meeting President Michel Suleiman and Prime Minister Saad Hariri.
The two-day visit will include a tour of villages along Lebanon's tense border with Israel and a rally in Beirut planned by Hizbollah.
Inside Lebanon, Hizbollah's rivals expressed concern about the visit. 250 Lebanese politicians, lawyers and activists wrote to Mr Ahmadinejad on Tuesday, criticising Tehran's backing of Hizbollah.
The letter said: “Your talk of 'changing the face of the region starting with Lebanon' and 'wiping Israel off the map through the force of the Islamic Resistance in Lebanon'... makes it seem like your visit is that of a high commander to his front line.”
Last week US State Department spokesman PJ Crowley expressed concern “that Iran, through its association with groups like Hizbollah, is actively undermining Lebanon's sovereignty.”
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