He also accused the United States, without naming it, of complicity in bringing about the destruction caused by Israel's 20-day-old offensive in Lebanon.
"We think that the protectors of the Zionist entity and those who support it are partners in these brutal crimes being committed against the innocent women and children" of Lebanon, Mottaki said.
He arrived in Lebanon on Monday, in the first visit by an Iranian official to war-torn Lebanon since fighting broke out between Israel and Hizbullah guerrillas three weeks ago. He traveled over land from neighboring Syria, since the country's only international airport was bombed in the first days of the war.
On Monday night, Mottaki met with Lebanese Foreign Minister Fawzi Salloukh and with French Foreign Minister Philippe Douste-Blazy, who was in Beirut for the third time since Hizbullah captured two Israeli soldiers and killed eight others on July 12, triggering the Israeli offensive.
Both meetings took place at the Iranian Embassy late Monday, but participants made no comments to the press.
Mottaki's visit coincided with a call on Muslim states by a top Iranian hard-line cleric, Ayatollah Ahmad Jannati, to provide weapons to Hizbullah to use in its fight against Israel, according to the semi-official Iranian Students News Agency.
"Now, it is expected that Muslim states not spare any assistance to Hizbullah and the Lebanese people, especially providing weapons, medicine and food," Jannati told ISNA.
It was not immediately clear if Jannati's comments represented the Iranian government. Jannati is the head of the powerful Guardian Council, a constitutional watchdog arbitrating between the parliament and the Iranian government.
It was not immediately known if Mottaki planned to meet Hizbullah's leader Sheik Hassan Nasrallah, as he traditionally has done on past visits to Lebanon.
Nasrallah has gone underground since the Hizbullah-Israeli fighting broke out three weeks ago. Israeli warplanes have destroyed his residence and office in south Beirut, but he has since given televised speeches.
Mottaki's visit comes a day after Israeli warplanes bombed a house in the southern Lebanese town of Kana, killing at least 56 civilians and provoking worldwide condemnation.
"Iran stresses the need for an immediate halt to the aggression launched by the Zionist entity on Lebanon," Mottaki said during a news conference Monday.
Mottaki also criticized the UN Security Council's inability to stop the conflict.
"The public opinion in the Islamic world and the international community are daily and frankly condemning the Israeli attacks on Lebanon, while we see international organizations are keeping silent," he said.
Iran and Syria are the principal sponsors of Hizbullah, and the two countries have applauded Hizbullah's capture of two Israeli soldiers, which triggered the Israeli offensive in Lebanon.
