"I think you're going to find in the weeks ahead in the confirmation process on David Friedman that it's going to be very clear that he wants -- he and President Trump want to be a part of achieving peace between Israelis and Palestinians -- and that some of the things he said don't really reflect what he believes," Lieberman said in an interview on "New Day."
"I think you'll find along the way that he will express some regrets," added Lieberman, a prominent Jewish American politician who also ran as Al Gore's vice president in 2000.
Friedman, a bankruptcy lawyer with long-held hardline views on Israel, was tapped to serve as US ambassador to Israel last Friday.
He courted controversy earlier this year when he called supporters of the progressive Jewish advocacy group J Street "worse than kapos" for supporting a two-state solution to Israeli-Palestinian conflict -- something he staunchly opposes. Kapos were Jews in Nazi concentration camps who were put in charge of other inmates and worked with the Nazis.
Lieberman said Thursday that "I totally disagree with that statement" about J Street and that it was "unfair and offensive."
"I've said this to David, and I think he will make clear that's one of the statements he regrets having made," he said.
Friedman has also said in the past that he does not believe Israeli settlement activity is illegal and opposes a ban on construction in the West Bank and East Jerusalem -- an issue that flared up on Thursday after the United Nations Security Council scheduled a vote on a draft resolution that would "immediately and completely cease all settlement activities in the occupied Palestinian territory, including East Jerusalem."
Trump put out a statement condemning the resolution, which is set to be voted on later Thursday.
"The resolution being considered at the United Nations Security Council regarding Israel should be vetoed. As the United States has long maintained, peace between the Israelis and Palestinians will only come through direct negotiations between the parties, and not through the imposition of terms by the United Nations. This puts Israel in a very poor negotiating position, and is extremely unfair to all Israelis," he said in the statement.
Trump's outspoken support for Israel in response to the UN resolution, coupled with the appointment of Friedman, portend a more robust engagement with Israel in the Trump administration -- potentially to the chagrin of some neighboring Arab States who are more sympathetic to the Palestine cause.
Still, Lieberman was insistent Thursday that "we're at a real moment of opportunity in the Middle East."
"It is quite clear than relations between Israel and the Arab nations are closer than they have ever been before, particularly because they share a concern, a fear, about Iran. They have common interests. But the Arab nations won't come out with this closer relationship to Israel, in my opinion, unless there's progress between the Israelis and Palestinians," he said.
And Lieberman -- who has expressed support for a two-state solution -- said that he didn't think Friedman's strident rhetoric on the issue was a cause for concern.
"When -- if -- he's confirmed as the ambassador to Israel, he is the representative of the President of the United States," he said. "So it's really a question of what the President of the United States has done."
Trump himself has not taken a clear position on a two-state solution, which is supported by the US and Israeli Prime Minister Benjamin Netanyahu.
"I've looked at every other alternative over the years, between achieving peace between Israelis and Palestinians, and you can't do it unless you recognize the right of the Palestinians to have their own state," Lieberman said. "This much I've heard President-elect Trump say -- he would really like to be a part of achieving the ultimate agreement between Israelis and Palestinians."