Israel warns of 'devastating consequences' as spike in fire with Lebanon risks wider conflict

A senior U.S. adviser will travel to Israel in a bid to cool rising tensions at the Lebanon border, where recent rains of missiles have reignited the risk of a broader conflict between the Jewish nation and Iran-backed militia.

Over the past week, Lebanese militant group Hezbollah has ramped up hostilities and cross-border missile attacks against targets in northern Israel, according to Israel Defense Forces and the Hezbollah-aligned al-Manar news outlet.

It comes amid a ramp-up in attacks by Hezbollah in recent weeks following repeat offensives against its neighbor since October.

The group is aligned with the similarly Iran-backed Palestinian militant organization Hamas, although Tehran denies that it commands these directly. Hezbollah claims solidarity with the Palestinian plight amid Israel's war campaign in the Gaza Strip.

Tensions have spiked on the border since the Israel Defense Forces on June 12 reported that an Israeli air strike in the southern Lebanese village of Jouaiyya killed a senior Hezbollah commander, Sami Taleb Abdullah, alongside three other group operatives.

The IDF claimed that Taleb Abdullah had "planned, advanced and carried out a large number of terrorist attacks against Israeli civilians," which CNBC could not independently confirm.

Israel has been responding to subsequent fire, with fighter jets most recently mobilizing against targets in four locations in southern Lebanon on Sunday, according to the IDF — which warned that further warfare could be afoot.

"[The] Hezbollah terror organization in Lebanon has been escalating its attacks against Israel," IDF Spokesperson Rear Admiral Daniel Hagari said in a video address on Sunday, claiming that the Lebanese militant group had fired over 5,000 rockets, anti-tank missiles and explosive drones at Israel since joining the conflict.

"Hezbollah's increasing aggression is bringing us to the brink of what could be a wider escalation, one that could have devastating consequences for Lebanon and the entire region," Hagari added. "Israel will take the necessary measures to protect its civilians, until security along our border with Lebanon is restored. One way or another, we will ensure the safe and secure of Israelis to their homes in northern Israel. This is not up for negotiation."

HoweveHezbollah deputy leader Sheikh Naim Qassem said last week that any Israeli expansion of the conflict in Lebanon will be met with "devastation, destruction and displacement" within the Jewish state, according to a Google-translated report from al-Manar.

He warned that Hezbollah has so far only used "a small portion of its capabilities in proportion to the nature of the battle."

Since last year, tens of thousands of Israelis and Lebanese people have been forced to flee their border-facing settlements as they fast became battlefields.

The latest tit-for-tat reprisals will be concerning for Washington, which has sought to contain tensions from sparking a chain reaction of hostilities between Israel and Hezbollah.

Amos Hochstein, a senior diplomatic adviser to the administration of U.S. President Joe Biden, is expected in Israel on Monday, an Israeli official told NBC News.

The White House views pacifying tensions between Lebanon and Israel and cease-fire talks in the Gaza Strip as interlinked, and the Biden administration is trying to gain traction behind its peace plan for the enclave.

The increase in Israeli-Hezbollah hostilities will also raise questions for market watchers who have already seen the Gaza war ripple into international trade. Claiming solidarity with the Palestinian cause, Yemen's Houthi — also backed by Iran — have delivered a series of naval attacks in the Red Sea, disrupting or stalling transit through a key trade route and effectively taking the waterway hostage.

On Sunday, the Yemeni group said it targeted three ships in the Red Sea, including a U.S. destroyer, according to a Google-translated update from Houthi spokesperson Yahya Sare'e – although it was unclear if any of the missiles had hit.