Mr Lieberman also leads a right-wing party, Yisrael Beiteinu
Israel's hardline Foreign Minister Avigdor Lieberman has told Israeli ambassadors to stop "grovelling" and defend their national honour.
He told a shocked audience of some 150 envoys in Jerusalem to "stop turning the other cheek" whenever Israel was insulted, Israeli media report.
The envoys were reportedly given no right of reply at the conference.
"We received a monologue without being able to hold a discussion," one unnamed ambassador told Haaretz newspaper.
'A response to everything'
Israel's top diplomat, who worked as a nightclub bouncer in his youth in the USSR, is known for his abrasive style. He famously once said that Egyptian President Hosni Mubarak could "go to hell".
"I have seen that some ambassadors identify themselves with the other side to such an extent that they are all the time trying to justify and explain," he told the ambassadors meeting at the foreign ministry, according to several reports of the event.
"Terms like 'national honour' have value in the Middle East," he was reported to have said.
"There must not be an attitude of obsequiousness and self-deprecation, and the need to always justify the other side. This is the wrong approach.
"We will not turn the other cheek. There will be a response to everything," the reports quoted him as saying.
In an editorial, the liberal Haaretz condemned Mr Lieberman's "shamefully bullying approach" and called for him to be sacked.