Irish citizens have been urged to avoid travelling to Israel due to “growing instability” in the region.
Citizens currently in Lebanon have also been advised to leave the country.
Recent days have seen growing tensions in the Middle East amid fears of a wider conflict in the region.
Taoiseach Simon Harris and Tánaiste Micheál Martin posted about the new travel advice on X, formerly Twitter.
Mr Harris said: “Our travel advice for Israel has changed due to growing instability in the region.
“The government is now advising Irish citizens do not travel to Israel.
“The same advice applies to Lebanon and Palestine.”
In his post, Mr Martin said travel advice had been updated.
He said: “I urge citizens to avoid all travel to Israel at this time.
“I also remind citizens to avoid travel to Lebanon.”
In a further post, he said: “I strongly advise Irish citizens in Lebanon to leave the country and take advantage of the commercial options still available.
“Safety and security of citizens is our priority.
“DFA (Department of Foreign Affairs) officials in the region and Dublin are available for consular advice.”
A travel alert on the DFA website advised against all travel to Israel, Palestine or Lebanon.
It said: “Irish citizens are strongly advised not to travel to border areas with Lebanon, as directed by local authorities.
“The Israeli military has announced that the area is a closed military zone and entry into the area is prohibited due to ongoing military operations.
“Further incidents can occur without notice and there is potential for intense escalation; extreme caution is advised.”
It added: “We strongly advise against all travel to the Gaza Strip, and to all border areas between the Gaza Strip and Israel, as directed by local authorities.
“Irish citizens in the Gaza Strip are advised to exercise extreme caution, and register their presence immediately by contacting the Embassy of Ireland in Tel Aviv.
“Due to the volatile security situation, we currently advise against all travel to the occupied West Bank, excluding East Jerusalem where we advise against non-essential travel. A number of crossings into Jordan remain open.
“The security situation across both Israel and Palestine remains tense and unpredictable, with the potential for intense escalation.”
It continued:”The Department strongly advises all Irish citizens currently in Lebanon to leave now while commercial options remain available.
“The situation in Lebanon remains highly volatile with intensifying clashes along the southern border in recent weeks.
“In light of the unpredictability of the situation, events could escalate throughout the country with very little warning. This could affect exit routes out of Lebanon.”