Hezbollah fighters.

Israel’s top national security advisor said that United Nations peacekeepers are failing to track Hezbollah arms in southern Lebanon.

“Under pressure, a multi-national force is like an umbrella that gets folded up on a rainy day,” Yaakov Amidror, Prime Minister Benjamin Netanyahu’s national security adviser, said in a Tel Aviv University speech, Reuters reported.

The United Nations Interim Force in Lebanon (UNIFIL) is a multi-national peacekeeping force established by the UN in the late 1970s to maintain peace in the region. Following the 2006 summer war between Hezbollah and Israel, its mission was beefed up to include “assisting the government of Lebanon to restoring authority in the area,” according to UNIFIL’s website.

Amidror also said that despite UNIFIL’s efforts, Hezbollah has continued to amass an arsenal of 60,000 rockets, including 5,000 long-range missiles capable of reaching Tel Aviv.

“Has Hezbollah avoided bringing any kind of rocket, missile or other arms into southern Lebanon because UNIFIL is there?” he said, according to Reuters.

While the northern border with Lebanon has remained largely quiet since the 2006 summer war, Israel is deeply concerned with Hezbollah gaining control of chemical weapons or other advanced weapons systems from Syria, amid the ongoing civil war there.

Hezbollah has recently come under increasing pressure both at home and abroad. The French government recently said that it would urge the European Union to designate Hezbollah as a terrorist organization.

Meanwhile, Lebanese Prime Minister Najib Mikati resigned last month over infighting in his government between the pro-Hezbollah Shi’a Muslim bloc and the Western-supported Sunni Muslim bloc. Mikati, who was originally backed by Hezbollah, fell into disfavor with the group following tensions over Hezbollah’s support for embattled Syrian President Bashar al-Assad.

Many Western-backed Sunni Muslims have sought to distance Lebanon from the fighting in Syria.