BEIRUT - Hezbollah leader Sayyed Hassan Nasrallah, speaking for the first time since the Israel-Hamas war erupted, warned on Friday that a wider conflict in the Middle East was a realistic possibility in a speech that was expected to indicate whether his group would wage a full-fledged war against Israel.

A formidable military force backed by Iran, Hezbollah has been engaging Israeli forces along the Lebanon-Israel border in the deadliest escalation since it fought a war with Israel in 2006.

Hezbollah have been escalating day by day, forcing Israel to keep its forces near the Lebanese border instead of the Gaza Strip and the occupied West Bank, Nasrallah said in a televised address.

"What's happening on the border might seem modest but is very important."

Nasrallah blamed the United States for for the war in Gaza and the high civilian death toll and that a de-escalation in the besieged enclave was vital to prevent regional war.

The Hezbollah chief thanked groups in Yemen and Iraq, part of what is known as the "Axis of Resistance". It includes Shi'ite Muslim Iraqi militias, which have been firing at U.S. forces in Syria and Iraq, and Yemen's Houthis, who have joined in the conflict by firing drones at Israel.

(Reporting by Laila Bassam, Thomas Perry and Riham al Koussa; Writing by Nadine Awadalla; Editing by Michael Georgy, Angus MacSwan and Tomasz Janowski)