BEIRUT (Reuters) - Syria's foreign minister offered on Sunday to join Hezbollah and said his country's army had standing orders to respond immediately to any Israeli attacks.

"If you wish, I'm ready to be a soldier at the disposal of (Hezbollah chief) Sayyed Hassan Nasrallah," Walid Mouallem told reporters on arrival in Lebanon in a symbolic gesture.

Asked about concerns that the war in Lebanon could spill over into a regional war, Mouallem said: "Most welcome".

"Syria is readying itself and doesn't hide its (military) readiness. We will respond to any Israeli aggression immediately," he added. Mouallem said later after talks with President Emile Lahoud: "If Israel attacks Syria by any means, on the ground, in the air, our leadership ordered the armed forces to reply immediately."

Mouallem, the first senior Syrian official to visit Lebanon since Syria ended three decades of military presence in April Last year, criticized a U.S.-French draft of a UN Security Council resolution to end the war.

"This draft resolution is a description for the continuation of the war because, unfortunately, it's not fair for Lebanon, therefore it's a plan for the possibility of the eruption of civil war in Lebanon and nobody, nobody, nobody has anything to gain from that happening, except Israel," he said.

A 26-day-old Israeli offensive designed to cripple Hezbollah in Lebanon has boosted the group's popularity among Arabs and cemented a personality cult around the charismatic Nasrallah.

"Sayyed Hassan Nasrallah and the Lebanese national resistance today are defending the dignity of the Arab nation and the unity of the nation like it is defending the dignity of Lebanon, the unity of Lebanon and the Lebanese people," Mouallem said.