US Defence Secretary Lloyd Austin met his Israeli counterpart Yoav Gallant at the Pentagon on Tuesday, warning that a conflict between Israel and Hezbollah could spark a regional war and urging a diplomatic solution.
More than eight months of Israel's war on Gaza has heightened tensions across the region, with Israeli forces and Lebanon's Iran-backed Hezbollah exchanging fire on a near-daily basis.
"Another war between Israel and Hezbollah could easily become a regional war, with terrible consequences for the Middle East," Austin said. "Diplomacy is by far the best way to prevent more escalation."
Gallant, speaking at the opening of the meeting with Austin, said that "we are working closely together to achieve an agreement but we must also discuss readiness on every possible scenario.
The Israeli army said last week that plans for an offensive in Lebanon were "approved and validated" amid escalating cross-border clashes, but Washington is seeking to lower the temperature and head off another major conflict in the Middle East.
Gallant is on a visit to Washington seeking to reaffirm the value of ties with Israel's top ally after Prime Minister Benjamin Netanyahu publicly chastised the United States for what he said was a delay in weapons deliveries.
The US government insists that only one shipment of bombs has been held up over concerns about their use in populated areas, and that other arms deliveries are proceeding as usual.
The United States is Israel's main supplier of weapons but the growing death toll from the Gaza conflict has piled pressure on President Joe Biden to take action and fueled tensions between his administration and Netanyahu.
Gallant met with Secretary of State Antony Blinken in Washington the previous day, with the top US diplomat calling on Israel to avoid escalation in Lebanon.
The Israeli minister also held talks with CIA chief Bill Burns, the key US point man in negotiations to free hostages from Hamas, which launched an unprecedented attack on Israel in October that sparked a devastating conflict in Gaza.
Netanyahu has said Israeli forces are winding up the most intense part of the Gaza war and will redeploy to the northern border, although he has cast the move as defensive.
Israel and Hezbollah last fought a full-scale war in 2006 that took a heavy toll on Lebanon, especially the country's south.