The government's SafeTravel website warned the security situation could get worse and flights out of the country could be disrupted or cancelled with little notice.
The Ministry of Foreign Affairs and Trade, which runs SafeTravel, also told citizens not to travel to Lebanon.
"We continue to advise that New Zealanders do not travel to Lebanon. If you are currently in Lebanon, we encourage you to leave now via commercial options.
"Airports and airlines may pause or cancel operations at short notice. If you choose not to leave while commercial flights are operating, be prepared to shelter in place for an extended period."
The travel advice - updated today - pointed to ongoing exchanges of fire at the border with Israel.
"There are ongoing exchanges of mortar and artillery fire in South Lebanon, on the border with Israel, and southern Beirut has also been impacted."
It also specifies that road transportation could be disrupted and New Zealanders in the country are responsible for their own departure.
Israel launched airstrikes against more than 1000 Hezbollah targets on Monday, killing 492 people and sending tens of thousands fleeing for safety in Lebanon's deadliest day in decades.
Meanwhile, Iran-backed Hezbollah has been firing rockets into Israel in support of Hamas, also backed by Iran.
The ongoing tensions followed the detonation of communication devices killing more then 30 people and injuring thousands more.
The government advice pointed out New Zealand did not have a diplomatic presence in Lebanon so the ability to provide assistance to citizens was limited.
The warning outlines ongoing unrest in the country due to various conflicts and prolonged economic challenges that were made worse by the Covid-19 pandemic.
"Some basic commodities (fuel, medicines, food) have become increasingly scarce due to the economic crisis," it states, adding that "power outages may affect critical infrastructure, such as hospitals" and they could also affect "other essential services such as food production and distribution."
The political situation in the country was "unpredictable", the advice said.
"Political developments in the region and international events can escalate tensions and result in outbreaks of civil unrest."
New Zealanders in the country were advised to "avoid all political demonstrations, rallies and large public gatherings as they could turn violent with little warning".
The advice referenced the conflict in Syria as having had a destabilising effect on the security situation in Lebanon, and said Israeli military action was ongoing "primarily against targets in Southern Lebanon".
Terrorism, kidnapping, landmines and violent crime were also listed as causes for concern.
