JERUSALEM - Israel's prime minister on Wednesday invited a hard-line rival to join his government, an official said, taking a bold but risky move that could shore up his shaky parliamentary coalition but deepen his international isolation.

An Israeli official said that Prime Minister Benjamin Netanyahu and Avigdor Lieberman, leader of the ultranationalist Yisrael Beitenu party, had agreed to appoint negotiating teams to hammer out the details of their alliance. Israeli media said that Netanyahu had offered Lieberman the post of defence minister, currently held by Moshe Yaalon.

The official, who spoke on condition of anonymity because he was not authorized to discuss the matter, could not confirm the reports about the Defence Ministry. A spokesman for Lieberman declined comment.

Lieberman, who has been both an ally and rival of Netanyahu's, has held a number of Cabinet posts in the past, including stints as foreign minister.

Lieberman, who was born in the former Soviet republic of Moldova, is one of the most polarizing figures in Israeli politics. With a tough-talking message that has questioned the loyalty of Israel's Arab minority, criticized the Palestinians and confronted Israel's foreign critics, he has at times alienated Israel's allies while becoming an influential voice at home.

With Israeli-Palestinian peace efforts in a deep freeze, Lieberman's addition to the government would push any hopes of reviving talks even further in the distance. Netanyahu is already facing criticism from his closest allies, the U.S. and key European countries, for not doing more to revive talks.

But with peace talks unlikely in any case, Netanyahu, whose coalition has just a one-seat majority in the 120-member parliament, appears to be more interested in expanding the government.

The Israeli official said that if there is a deal, both men would "remain committed to two states for two peoples." He noted that a right-wing government reached peace with Egypt and described Lieberman as "pragmatic."

The move came after days of speculation that the opposition Labor party would join the coalition.

Opposition head Isaac Herzog said he will work to topple the "crazy right-wing government."

While Yariv Levin, of Netanyahu's Likud party, said Lieberman will bring the government "stability."

If Netanyahu brings in Lieberman, it is unclear what will happen to Yaalon, a former military chief of staff who is generally respected for his knowledge of military affairs.

Netanyahu and Yaalon have clashed in recent days over the role of the military in public discourse. A top general infuriated Netanyahu earlier this month when he compared the atmosphere in Israel to Nazi-era Germany, while Yaalon backed the general's right to express his views.

In March, military leaders criticized a soldier who was caught on video fatally shooting an already-wounded Palestinian attacker in the head — and he is now on trial for manslaughter. While Yaalon has backed the military, hard-liners, including Lieberman, have backed the soldier. Netanyahu, for his part, called the soldier's family to express sympathy.

Lieberman, 57, rose to prominence as the engineer of Netanyahu's successful run for prime minister in 1996, and he later became Netanyahu's chief of staff. He is a powerful behind-the-scenes mover who lives in a West Bank settlement.

In the past, Lieberman has pushed for legislative proposals that critics said were discriminatory against Israel's Arab minority, including a failed attempt to require that Israelis sign a loyalty oath or have their citizenship revoked. He has expressed skepticism over pursuing peace with the Palestinians, and is now pushing a proposal to impose the death penalty against Arabs convicted of acts of terrorism.

Lieberman's tough stances have long stoked controversy. As a Cabinet minister last decade, he called for the bombing of Palestinian gas stations, banks and commercial centres. He said former Egyptian President Hosni Mubarak could "go to hell" and once even threatened to bomb the Aswan dam.

He also led a recent parliamentary drive to exclude Arab parties from running for election — a move that was overturned by Israel's Supreme Court.

Despite his rhetoric, Lieberman has shown signs of pragmatism. He served as a Cabinet minister in two centrist Israeli governments, though he was fired for opposing the 2005 withdrawal from Gaza and resigned to protest peace talks begun at the 2007 conference in Annapolis, Md. His plan for redrawing Israel's borders would also mean dismantling some Jewish settlements, possibly his own.

News from © The Associated Press, 2016