A senior U.S. official said on Tuesday there was a "real opportunity" to end the conflict between Israel and Hezbollah and that gaps were narrowing, signalling progress in Washington's efforts to clinch a ceasefire agreement.

Some of the weapons, which include modern antitank missiles, have come from Russian stockpiles in neighboring Syria.

Amos Hochstein is expected in Beirut on Tuesday, according to two Lebanese official sources, in a sign of progress in ceasefire negotiations for the deadly cross-border conflict between Israel and Hezbollah in Lebanon.