The United States wants UN peacekeepers in southern Lebanon to take on an expanded mission and investigate alleged violations by Hezbollah militias in the volatile area, Ambassador Nikki Haley said Monday. 
The UN Security Council is set to vote on renewing the UN interim force in Lebanon (UNIFIL) later this month, and Haley said she will seek "significant improvements" to its mandate.
UN Secretary-General Antonio Guterres informed the council in a letter sent on Friday that he intended to look at ways in which UNIFIL could beef up its efforts "regarding the illegal presence of armed personnel, weapons or infrastructure inside its area of operations."
"We share the secretary-general's strong desire to enhance UNIFIL's efforts to prevent the spread of illegal arms in southern Lebanon," said Haley in a statement.
"These arms –- which are almost entirely in the hands of Hezbollah terrorists –- threaten the security and stability of the region."
"UNIFIL must increase its capacity and commitment to investigating and reporting these violations," she added.
Guterres is expected to discuss UNIFIL's mission when he pays his first visit as UN chief to Israel and the Palestinian territories later this month. 
Haley has been a strong supporter of Israel, which fought a month-long war against Hezbollah in 2006. The fighting killed more than 1,200 Lebanese, mostly civilians, and more than 160 Israelis, mostly soldiers.
There has been speculation about the possibility of a new war breaking out between Israel and Hezbollah, a powerful Lebanese paramilitary organization, more than a decade after their last direct confrontation.
There have been periodic skirmishes along the UN-monitored demarcation line between Israel and Lebanon, longtime adversaries which are technically still at war with each other.
Set up in 1978, UNIFIL was beefed up after the 2006 war and now has 10,500 troops on the ground monitoring the ceasefire and helping the Lebanese government secure its borders.
A vote on UNIFIL's mandate at the council is tentatively scheduled for August 30.