U.N. aid chief Tom Fletcher on Thursday expressed concern that the conflict between Israel and Hezbollah in southern Lebanon could be long-lasting, potentially resulting in a "fresh occupation."

Eighteen European countries on Thursday urged Israel and Hezbollah to stop fighting as their latest conflict reached one month and with fears over Israeli plans to control part of southern Lebanon post-war.

International Organization for Migration chief Amy Pope told AFP on Thursday in Beirut that the prospects for prolonged mass displacement in Lebanon, where Israel and Hezbollah are at war, were "very alarming".

The Egyptian intelligence's initiative for a ceasefire between Hezbollah and Israel remains stalled "in the study and consultation phase," with no final response yet from either side, despite Speaker Nabih Berri's involvement in the negotiations, sources told the Nidaa al-Watan newspaper.

MP Ghayath Yazbek of the Lebanese Forces said Thursday that an "Iranian-made" drone that crashed earlier in the day in the Batroun district had been headed to the nearby Hamat airbase, which is used by U.S. forces, suggesting that Hezbollah and Iran were behind it.

Israeli Defense Minister Israel Katz on Thursday warned that Hezbollah chief Sheikh Naim Qassem would pay an "extraordinarily heavy price" for escalating attacks during the ongoing Jewish holidays.

"I have a clear message for Naim Qassem... you and your associates will pay an extraordinarily heavy price for the intensified rocket fire directed at Israeli citizens as they gathered to celebrate Passover Seder," Katz said in a video statement.

A month into Israel's war against Hezbollah, invading Israeli troops are gradually advancing in south Lebanon, raising fears for the area's fate following the last Israeli occupation that lasted nearly two decades.

Since war erupted last month, Israeli officials have said Israel intends to establish a "security zone" inside Lebanon.

Prime Minister Nawaf Salam reiterated, after a cabinet session at the Grand serail, his commitment to efforts aiming at stopping the Israeli war.

Salam condemned joint Hezbollah-Iran attacks on Israel and said they do not serve Lebanon's national interests.

In rugged terrain along the Syrian-Lebanese border, yellow bulldozers raised earthen berms in front of armored vehicles while soldiers combed through tunnels they said were used by Hezbollah, as Syria reinforces its side of the border.

Syria is seeking to stay out of the regional war, whose flames have reached neighboring Lebanon, where Hezbollah is fighting a fierce conflict with Israel.

President Joseph Aoun and Prime Minister Nawaf Salam are determined to continue their contacts, hoping that will lead to international intervention to halt the fighting in south Lebanon, ministerial sources said.