The UN peacekeeping force in Lebanon, criticized by the United States and Israel, needs to be "more agile and mobile," UN chief Antonio Guterres said in a report published Tuesday ahead of the mission's renewal in August.
"Standard armored personnel carriers are not entirely suitable for crowded areas, narrow streets and mountainous terrain," Guterres said.
With lighter transport vehicles, troops would have fewer restrictions on their movement, he said.
He also called for "better situational awareness" for UNIFIL.
Lebanon and Israel are still technically at war, and UNIFIL usually patrols the border between the two.
Set up in 1978, UNIFIL was beefed up after a months-long war in 2006 and tasked with guaranteeing a ceasefire and Israeli withdrawal from a demilitarized zone on the border.
UNIFIL can have up to 10,000 troops on the ground, monitoring the truce and helping Lebanese troops secure the borders.
Guterres said the changes could come from "replacing some heavy infantry functions used for day-to-day activities with reconnaissance functions" using smaller "high-mobility light tactical vehicles and reconnaissance vehicles with improved monitoring capacity," he noted.
The shift "would result in a force sufficiently protected but with a lighter footprint, geared towards better situational awareness," he said.
That could mean more troops working in observation and surveillance missions and a reduction in the number of battalions in the zone of operations, he said.
The UN head said he wanted to see construction of observation posts and for UN troops to have modern technology to collect and analyze data and improve their communications.
As well as the video surveillance and sensors already deployed, Guterres called for thermal-imaging cameras, hi-tech binoculars and drones which could bolster surveillance capacity, in particular on the Blue Line separating Lebanon from Israel.
Focusing on its mission to deter any further hostilities, the United Nations Interim Force in Lebanon currently relies on a "saturation model" of deploying a high density of soldiers and hardware.
In recent years, Israel and the United States have frequently criticized the mission -- which is a peacekeeping operation rather than an enforcement mission -- for not going on the offensive enough.
At the end of May, the Shia movement Hezbollah rejected a US demand to bolster the UN mission by giving it authority to search private property.
Without referring to that explicitly, Guterres said in the latest report that UNIFIL should continue tackling different parties that do not respect their obligations to the mission.
On the one hand, Hezbollah and other groups hold weapons that are beyond the control of the Lebanese state, which hinders its sovereignty across the country.
On the other side, Israel carries out flights over Lebanese territory almost every day, including for raids into Syria, which compromises the credibility of the UN mission, Guterres said.