The Western-backed March 14 coalition won an unexpectedly large parliamentary majority – 71 of 128 seats – over the opposition, led by the Iranian-backed militant group.
A win for Hezbollah and its allies Sunday would tip the region’s balance of power toward Iran.
The US Secretary of State dropped into Beirut Sunday to bolster US allies against Hezbollah supporters ahead of close parliamentary elections.
In another nod to the West, Syria also sent an ambassador to Iraq – the first in decades.
Lebanese President Michel Suleiman's visited Damascus Wednesday, raising the prospect that perhaps hundreds of detainees in Syria will be released.
Fighting in Tripoli is indicative of rising Sunni-Shiite tensions as the formation of a new government hits an impasse. Religious leaders called for calm Wednesday.
The agreement gives Hezbollah and the opposition allies of the Shiite militants enough control in the government to have veto power over legislation.