Vice President Kamala Harris, the presumptive Democratic election nominee, said Tuesday that Israel had a "right to defend itself" following a strike in Hezbollah's stronghold in southern Beirut.

Harris — who last week struck a tough tone with Israeli Prime Minister Benjamin Netanyahu over Israel's war on Gaza — also called for a diplomatic solution to reduce the risk of all-out conflict on the Lebanon-Israel border.

"I want to address what's happened over the last few hours in terms of the Middle East, and be very clear Israel has a right to defend itself," Harris told reporters as she headed to an election rally in Atlanta.

Israel said the attack on Tuesday had targeted a Hezbollah commander responsible for rocket fire that killed 12 children in the occupied Golan Heights at the weekend.

"What we know in particular is it [Israel] has the right to defend itself against a terrorist organization, which is exactly what Hezbollah is," added Harris.

"But all of that being said, we still must work on a diplomatic solution to end these attacks, and we will continue to do that work."

Harris is effectively locked in as the Democratic presidential nominee for November's election after President Joe Biden's decision to drop out of the White House race just over a week ago.

With speculation swirling about whether she would moderate Biden's stalwart support for Israel's Gaza war, Harris said last week after meeting Netanyahu in Washington that she "will not be silent" about Palestinian casualties there.

Harris said on Thursday she expressed "serious concern about the scale of human suffering" to Netanyahu, who held separate meetings with her and Biden.