The U.S. has "relayed" to Iran that Israel will not further escalate its attacks in Lebanon as the Trump administration seeks to get high-stakes nuclear talks with Iran back on track, a source familiar with the matter told CNN.

Iran has informed Hezbollah that it will not continue the negotiations with the US without a comprehensive ceasefire in Lebanon, Hezbollah MP Hassan Fadlallah said.

Israel’s military struck targets throughout southern Lebanon overnight into Friday and Hezbollah reported intense fighting in the area, threatening the nascent agreement between Iran and the United States to end their war. Lebanese media reported at least 18 people killed in the strikes, and Israel said four soldiers died, vowing to make Hezbollah pay a heavy price.

U.S. President Donald Trump said Friday that he can restrain Israel from attacking Lebanon.

"They have a lot of respect for me, and they do as I say," he told an interviewer on a televised show.

Israel said Friday four of its soldiers were killed in south Lebanon amid clashes with Hezbollah.

Lieutenant Colonel Dor Gedalia Ben Simhon "fell in combat" along with three other soldiers whose names will be released later, the military said in a statement.

The United States is "committed to PEACE," and we "encourage everyone in the Middle East Region to maintain their commitment to allowing our negotiations to beautifully unfold," U.S. President Donald Trump said overnight.

"The Markets are loving what is happening with Oil Prices way down, and Stocks way up. We expect a complete Ceasefire on all fronts, including Lebanon, Hezbollah, and Israel," Trump urged.

The U.S. Treasury on Thursday imposed sanctions on Marada Movement chief Suleiman Franjieh, Hezbollah political council deputy head Mahmoud Qmati and other individuals for using their influence to "obstruct Lebanon's peace process and delay the disarmament of Hezbollah."

Israeli Prime Minister Benjamin Netanyahu announced Thursday that Israel's "struggle" is not over yet, and that more challenges lie ahead, after the U.S. and Iran signed an MoU to end the war between them, which also inlcudes a clause about stopping the conflict in Lebanon and respecting its sovereignty and territorial integrity.

Israeli commanders and soldiers currently involved in the fighting in Lebanon say the Israeli army has changed its open-fire rules in recent days, reducing troops' ability to "prevent and respond to Hezbollah attacks" and leaving soldiers vulnerable.

According to Israel's Channel 14, the next steps in south Lebanon will be discussed during next week's negotiations with Lebanese representatives in Washington.

Israeli security sources said the current agreement does not include an Israeli withdrawal from Lebanon and that Israel will retain "full freedom of action" to "strike against any threat" in Lebanon.

President Joseph Aoun said Thursday that the latest war has disrupted the economic, financial, administrative, and judicial reforms in Lebanon.

"Lebanon does not need financial aid but investments," he said.