"There is no military solution, only diplomacy, dialogue and full implementation of the UN Charter and Security Council resolutions. The diplomatic avenues are available, including through my special coordinator for Lebanon... and through key member states," he said.

Lebanon was dragged into the Middle East war last week when militant group Hezbollah attacked Israel in response to the killing of Iranian supreme leader Ayatollah Ali Khamenei in US-Israeli strikes.

"We are doing everything we can now to bring about an immediate de-escalation and the cessation of hostilities," Guterres told reporters.

"My special coordinator is engaging with all actors around the clock to bring the parties to the table and UNIFIL peacekeepers... remain in position," he said, referring to the UN Interim Force in Lebanon.

He said attacks against peacekeepers and positions were "completely unacceptable and they must stop. They are in breach of international law and may constitute war crimes".

Three peacekeepers serving with the Ghanaian contingent were wounded earlier this month in south Lebanon.

Guterres arrived in Beirut on Friday for what he called a "solidarity" visit, and launched a $325 million humanitarian appeal to support Lebanon as it responds to the displacement crisis.

On Saturday, he urged support for the Lebanese government, which last year committed to disarming Hezbollah.

"My message to the international community is simply step up your engagement, empower the Lebanese state and support the Lebanese Armed Forces to secure the capabilities and resources they need. Respond generously to the humanitarian appeal," he said.

The Israeli army has issued sweeping evacuation orders to residents of south Lebanon and Beirut's southern suburbs, with the Norwegian Refugee Council saying they cover 14 percent of Lebanese territory.

"Evacuation orders in a situation where so many vulnerable populations exist in the areas that are asked to be evacuated does not create enough security for civilians, and whatever does not create enough security for civilians inevitably becomes in violation of international humanitarian law," Guterres said.