Saudi Arabia is to give Lebanon's army a grant of $3bn (£1.8bn, 2.8bn euros).
Lebanese President Michel Sleiman made the announcement in a televised address after the funeral of a senior Lebanese politician killed in a car bomb attack. He said it would help fight terrorism.
Mohamad Chatah, a Sunni Muslim, was a staunch critic of Syrian President Bashar al-Assad and Lebanon's Shia Hezbollah movement that backs him.
Saudi Arabia and Hezbollah have taken opposite sides in the Syrian conflict.
