U.S. President Donald Trump on Thursday accused Iran of doing a "very poor job" of allowing oil through the Strait of Hormuz and of breaching the terms of their two-week ceasefire agreement.

In a barrage of social media posts that sparked fresh fears for the shaky truce, Trump also warned Iran against imposing a toll for ships passing through the crucial waterway.

Pakistan was poised on Friday to host Iranian and U.S. delegations for negotiations in its capital, although Tehran's participation remained uncertain after deadly Israeli strikes on Lebanon threatened this week's temporary truce.

Israel's army Chief of Staff Eyal Zamir visited ground troops in southern Lebanon on Thursday, telling them Hezbollah suffered a "heavy blow" from its major bombardment targeting the Iran-backed group a day earlier.

A Hezbollah lawmaker on Thursday reiterated his group's rejection of any direct negotiations between Lebanon and Israel, after Israeli Prime Minister Benjamin Netanyahu said he had ordered his cabinet to begin talks with Beirut.

The Israeli army said Thursday it was striking Hezbollah positions in Lebanon, shortly after it had warned that the group could expand launches of projectiles across Israel.

Lebanon's health ministry said Thursday that Israeli strikes across the country a day before killed more than 300 people and wounded at least 1,150.

Israel and Lebanon will hold talks next week in Washington after Israeli Prime Minister Benjamin Netanyahu ordered direct talks, a U.S. official said Thursday.

U.S. President Donald Trump told NBC News on Thursday he was "very optimistic" about a peace deal with Iran after their ceasefire, and that Israel was "scaling back" strikes in Lebanon.

Lebanon wants a ceasefire before starting any negotiations with Israel, a Lebanese government official told AFP on Thursday, after Israeli Prime Minister Benjamin Netanyahu said he had ordered his cabinet to begin direct talks with Beirut.

Israeli Prime Minister Benjamin Netanyahu said Thursday he ordered his cabinet to open direct talks with Lebanon to disarm Hezbollah and establish "peace relations" between the two countries.