U.S. envoy Amos Hochstein will hold talks with Lebanese officials in Beirut on Monday on conditions for a ceasefire between Israel and Iran-backed Hezbollah, two sources told Reuters, as Israel expanded its air campaign on the group's assets overnight, Paralel.Az reports citing Reuters.

While Hochstein is likely to push for calm after a year of fighting during which Israel killed leaders of both Hezbollah in Lebanon and Hamas in Gaza, the U.S. has made it clear it will show unwavering support for Israel despite rising death tolls.

The U.S. military has rushed its advanced anti-missile system to Israel and it is now "in place", U.S. Defense Secretary Lloyd Austin said during a trip to Kyiv.

Austin declined to say whether the Terminal High Altitude Area Defense system, or THAAD, was operational. But he added: "We have the ability to put it into operation very quickly and we're on pace with our expectations."

Israel overnight attacked sites in Beirut, southern Lebanon and the Bekaa valley that it said are used by Hezbollah to finance its operations. Hundreds of families fled homes near the targeted locations ahead of the strikes, with no casualties reported.

Israel has reportedly given the United States a document with its conditions for a diplomatic solution to end the war in Lebanon, Axios reported on Sunday, citing two U.S. officials and two Israeli officials.

Israel has demanded its forces be allowed to engage in "active enforcement" to make sure Hezbollah doesn't rearm and rebuild its military infrastructure close to the border, Axios reported, citing an Israeli official.

Israel also wants its air force to have freedom of operation in Lebanese airspace, the report added. A U.S. official told Axios it was highly unlikely that Lebanon and the international community would agree to Israel's conditions.

Hochstein is set to meet Lebanon's caretaker prime minister Najib Mikati and speaker of parliament Nabih Berri on Monday.

Berri told the Al-Arabiya broadcaster over the weekend that Hochstein's visit was "the last chance before the U.S. elections" to reach a truce and said he would reject any amendments to United Nations resolution 1701, which ended the last bloody conflict between Hezbollah and Israel in 2006.

Cross-border fighting between Israel and Hezbollah erupted a year ago when the group began launching rockets in support of Palestinian militant group Hamas in Gaza.

At the start of October, Israel launched a ground assault inside Lebanon in an attempt to stabilise the border region for its citizens who had fled rocket attacks in northern Israel.

It has also assassinated senior Hezbollah figures, including its veteran leader Hassan Nasrallah who was killed in an aistrike in Beirut's southern suburbs.

The U.S. and regional powers have tried for a year to secure a ceasefire in Gaza but the efforts have been unsuccessful, leaving Lebanese officials and many diplomats sceptical about the chances for a truce in Lebanon.