The US-mediated ceasefire, which is set to expire on Sunday, has yielded a significant reduction in violence, but attacks have continued in southern Lebanon, where Israeli troops have seized a self-declared buffer zone.
Iran-backed Hezbollah says it has "the right to resist" occupying forces.
Wednesday marked Lebanon's deadliest day since the ceasefire took effect on April 16.
Those killed by Israeli strikes included Lebanese journalist Amal Khalil, according to a senior Lebanese military official and her employer, the Al-Akhbar newspaper.
Hostilities between Hezbollah and Israel reignited on March 2, when the group opened fire in support of Tehran in the regional war.
The ceasefire in Lebanon emerged separately from Washington's efforts to resolve its conflict with Tehran, though Iran had called for Lebanon to be included in any broader truce.
Hezbollah said it carried out four operations in south Lebanon on Wednesday, saying they were a response to Israeli strikes.
Almost 2500 people have been killed in Lebanon since Israel went on the offensive in response to Hezbollah's March 2 attack, according to Lebanese authorities.
Israel is occupying a belt of the south that extends 5km to 10km into Lebanon, saying it aims to shield northern Israel from attacks by Hezbollah, which has fired hundreds of rockets during the war.
The Lebanese government has opened direct contacts with Israel despite strong objections from Hezbollah, which was established by Iran's Revolutionary Guards in 1982.
Lebanese President Joseph Aoun has said Beirut's envoy to Thursday's talks in Washington, Lebanese ambassador to the US Nada Moawad, would seek a ceasefire extension and a halt to demolitions being carried out by Israel in villages in the south.
A Lebanese official said Beirut wanted a ceasefire extension as a prerequisite for talks to expand beyond the ambassadorial level to the next phase, in which Lebanon would push for an Israeli withdrawal, the return of Lebanese detained in Israel and a delineation of the land border.
Israel says its objectives in the talks with Lebanon include securing the dismantlement of Hezbollah and creating conditions for a peace deal.
Israel has sought to make common cause with the Lebanese government over Hezbollah, which Beirut has been seeking to disarm peacefully for the past year.
US Secretary of State Marco Rubio is set to attend Thursday's meeting.
Israel will be represented by its ambassador to Washington, Yechiel Leiter.
Rubio hosted the first meeting between Leiter and Moawad on April 14 - the highest-level contact between Lebanon and Israel in decades.
Washington has denied any link between its Lebanon mediation and diplomacy over the Iran war.
Hezbollah says the Lebanon ceasefire was the result of Iranian pressure rather than US mediation.
