"I am here on a visit of solidarity with the people of Lebanon," he said. "Solidarity in words must be matched by solidarity in action. This aid is urgently needed. The military escalation across the region is taking a terrible toll, including in Lebanon."

Amid the ongoing Middle East crisis, hundreds of civilians have been killed - including many children - and entire communities have been uprooted as "lives have been turned upside down."

Access to food, water, healthcare, education and basic services has been dangerously disrupted, and evacuation orders now extend across more of the country than ever before.

In addition, more than 90,000 people - mostly Syrians, but also Lebanese - have crossed into Syria.

Ceasefire needed now

The appeal's success depends on swift, flexible funding and on ensuring that humanitarian workers can safely reach those most in need, the Secretary-General emphasised.

"These are immediate needs, but there will be a lot that Lebanon needs in solidarity from the international community," he said.

"Helping to establish and immediate ceasefire that both sides must accept, creating the conditions for negotiations that will allow Lebanon to become in the shortest possible period, a country that sees its territorial integrity fully respected and where the State has the monopoly of the use of force," he said, adding that the UN stands ready to support the government.

Solidarity on the ground

Mr. Guterres said that for years, Lebanon has opened the doors to those fleeing conflict, showing the world the true meaning of hospitality, solidarity and resilience.

"Now, the world must show the people of Lebanon our strongest support in this hour of grave danger and profound need," the UN chief said.

"In the face of this upheaval, we have seen exceptional courage and solidarity on the ground," he continued, pointing to schools that have opened their doors to shelter displaced families and health workers who continue to serve under immense pressure.

UN supports lifesaving efforts

"United Nations agencies and humanitarian partners are working closely with national authorities to respond with urgency, delivering hot meals, safe drinking water, hygiene supplies and essential relief items," he said.

"These efforts are saving lives, but they need a big boost of support."

The newly launched flash appeal will sustain and expand lifesaving assistance over the next three months, including food, clean water, health care, education, protection and other vital services, he said.