Lebanese President Michel Aoun said on Saturday that any Israeli attempt to violate Lebanon's sovereignty would be met with the "appropriate response", in a statement released by his office.
"Any attempt to hurt Lebanese sovereignty or expose the Lebanese to danger will find the appropriate response," the statement said.
Last week, Aoun said in an interview that Hezbollah must arm itself to complement the Lebanese army's ability to deal with Israel. In response, Israel's Permanent Representative to the UN, Amb. Danny Danon, sent a letter to Secretary-General António Guterres and to the Security Council.
Aoun's statement said he was reacting to remarks in Danon's letter, which amounted to a "masked attempt to threaten security and stability" in southern Lebanon, but did not say what the remarks were.
Israeli Intelligence Minister Yisrael Katz said on Thursday that all of Lebanon would be a target if Hezbollah fired on Israel.
Aoun's comments also followed warnings this week by the leader of the armed Lebanese Shi'ite group Hezbollah, a political ally of the president, against any Israeli aggression.
Sayyed Hassan Nasrallah said the group's rockets had the ability to strike Israel's nuclear reactor at Dimona and its military infrastructure—an apparent warning against any Israeli military action that he said might be approved by the new US president, Donald Trump.
Trump's administration has been vocal in its criticism of Hezbollah's patron Iran and in its support for Israel.
Speaking in a meeting with visitors to Beirut's presidential palace, Aoun said on Saturday that Danon's letter "constitutes a threat to Lebanon. The international community should be wary of Israel's aggressive intentions against Lebanon."
The president also said, referring to the 2006 resolution that ended the Second Lebanon War, "Who need to implement Security Council resolutions is Israel, before others. Israel still refuses to implement Resolution 1701, moving from the cessation of hostilities phase to the ceasefire stage, despite more than 11 years having passed since the resolution was released."
Roi Kais and Itamar Eichner contributed to this report.