Protest errupted in Libya and its PM has suspended foreign minister after she met informally with her Israeli counterpart, reports BBC.
Libya is known as a strong backer of the Palestinian cause who does not recognise Israel. And the meeting has sparked protests in the majority Arab state.
Israeli FM Eli Cohen said the "historic" meeting was "the first step" in establishing relations with Libya.
Israel is working to build closer ties with Arab and Muslim-majority countries which do not officially recognise it.
However Libya's presidential council, which represents its three provinces, said it was illegal to normalise relations with Israel.
The Speaker's Office in parliament accused Najla Mangoush of grand treason, and Prime Minister Abdul Hamid Dbeibah has referred her for investigation.
The announcement by Israel that talks had taken place was surprising given that it was not known to be courting Libya, a staunch foe and champion of the Palestinian struggle, especially under former Libyan leader Muammar Gaddafi.
The statement was also unusual in its level of detail, perhaps intended to offset any anticipated denial from the Libyan side - also by identifying and acknowledging Italian foreign minister Antonio Tajani for hosting the meeting in Rome.
On Monday, an Israeli official told the BBC that the meeting was planned in advance and was not a chance encounter, like Libya's foreign ministry had portrayed it.
The official stressed that the two sides agreed what would be emphasised in the published statement, which he said had been due to be published on Monday but was released on Sunday after the story was leaked to the Israeli media.
Israeli opposition leader Yair Lapid accused the Israeli foreign ministry of being "amateurish [and] irresponsible" and having committed "a serious failure of judgment".
Another opposition leader, Benny Gantz, accused the Israeli government of doing "everything for PR and headlines, with zero responsibility and forward thinking".
In his statement on Sunday, Mr Cohen said he met Ms Mangoush last week on the sidelines of a summit, and that they discussed "the great potential for the relations" between Israel and Libya.
He said they talked about Israeli aid in humanitarian issues, agriculture, water management and the importance of preserving Jewish heritage in Libya, including renovating synagogues and cemeteries.
Bd-pratidin English/Lutful Hoque
