Lebanon was pulled into the Middle East war on March 2 after militant group Hezbollah fired rockets at Israel in support of its backer Iran. Israel has responded with huge strikes and a ground invasion in the country's south.

Falconer said that "this is not a conflict of Lebanon's making. There must be a ceasefire. We welcome the talks that have started."

"The strikes in Lebanon have had a terrible effect on civilians," he said.

"Hezbollah must stop firing" and must be disarmed, he said, adding that "it must be the Lebanese government that monopolises the use of force in Lebanon".

Lebanon says the conflict has killed more than 2,100 people and displaced more than one million.

Israel and Lebanon agreed on Tuesday to begin direct negotiations following a meeting between the Israeli and Lebanese ambassadors to the United States.

"It's very welcome that they've had the direct contact in Washington on Tuesday," Falconer said.

An Israeli minister said Prime Minister Benjamin Netanyahu would speak to Lebanese President Joseph Aoun on Thursday, but Aoun's office has not confirmed the call, stressing the importance of a ceasefire before any direct negotiations.

Falconer also said that "we want to see the Strait of Hormuz reopened in accordance with international law," ahead of a video conference on Friday co-hosted by Britain and France on the critical waterway.

The Middle East war since late February has brought key oil and gas shipping through the strait to a near halt.