The US State Department updated its travel advisory for American citizens yesterday (Saturday) to Level 4 or "Do Not Travel" due to the increased risk of escalation between Israel and Hezbollah and even outright war.
The advisory states that "the U.S. Embassy urges U.S. citizens to depart Lebanon while commercial options still remain available. At this time, commercial flights are available, but at reduced capacity. If the security situation worsens, commercial options to depart may become unavailable."
The advisory also warned that "the U.S. Embassy may not be able to assist U.S. citizens who choose to remain" and that "the U.S. Embassy strongly encourages U.S. citizens in Southern Lebanon, near the borders with Syria, and/or in refugee settlements to depart those areas immediately."
Regarding those who nevertheless choose to remain or travel to Lebanon, the State Department said that citizens in Lebanon should have a family point of contact in case of abduction, always keep travel and other key documents easily accessible, and do not touch any unknown metal objects, as these might be unexploded ordnance.
The advisory also said citizens should keep solely to areas frequented by westerners and well-known roads.