Lebanese forces last weekend captured a compound in the coastal city of Sidon held by militant Sunni cleric Ahmad Assir, a staunch opponent of Syrian President Bashar Assad and his Shiite supporters, Hezbollah. At least 17 members of the Lebanese military were killed in the melee.
The official National News Agency reported "Salafist gunmen" were locked in battle Friday with the Lebanese military in the Abra district of Sidon. There were no indications of casualties or the number of people engaged in the battle.
Lebanon's national security is under threat from Syria's civil war. Lebanon broke free of Syrian dominance following the Cedar Revolution of 2005 and spillover threats have rekindled tensions.
"Kerry noted that the United States would take all necessary steps to encourage the international community to continue to strongly promote and protect Lebanon's sovereignty, independence and security," a statement from the State Department said.
U.S. deputy envoy for refugees Anne Richard met in person with Lebanese officials Thursday, thanking the government for its support for Syrian refugees.