Saudi crown prince Mohammed bin Salman has gone “full gangster”, US senators said at a confirmation hearing for Donald Trump’s nominee to be US ambassador to the Middle Eastern kingdom.

Both Republican and Democrat senators at retired general John Abizaid‘s confirmation condemned Saudi Arabia’s conduct in Yemen‘s civil war and its heavy-handed diplomacy.

They also criticised the kingdom for its human rights abuses including the torturing of women’s activists and a US citizen, and the murder of journalist Jamal Khashoggi.

Mr Abizaid called for accountability for the murder of Mr Khashoggi, a US resident, and support for human rights, but repeatedly stressed the strategic importance of Washington-Riyadh ties.

Despite increasing tension between the two countries, the United States has not had an ambassador to Saudi Arabia since Trump became president in January 2017.

Jamal Khashoggi death: key figures Show all 7 1 /7 Jamal Khashoggi death: key figures Jamal Khashoggi death: key figures Jamal Khashoggi Washington Post journalist who was critical of the Saudi regime and the young Crown Prince Mohammed bin Salman, he was murdered on 2 October in the Saudi Arabian consulate in Istanbul AFP Jamal Khashoggi death: key figures Saudi Crown Prince Mohammed bin Salman Heir to the Saudi throne, Mohammed bin Salman has been implicated in the murder, with US officials claiming that he must have known of the plot AFP/Getty Jamal Khashoggi death: key figures 15 man hit squad Turkish police suspect these 15 men of being involved in the murder of Jamal Khashoggi, issued 10 October, 8 days after the journalist disappeared EPA Jamal Khashoggi death: key figures Saud al-Qahtani Aide to Crown Prince Mohammed bin Salman, Saud al-Qahtani is claimed to have ordered Khashoggi's murder Saud Al-Qahtani/Twitter Jamal Khashoggi death: key figures Maher Abdulaziz Mutreb A former diplomat who often travelled with the Crown Prince, Mutreb was initially claimed to be the leader of the hit squad and is pictured here entering the Saudi consulate on the day of the murder AP Jamal Khashoggi death: key figures Mustafa al-Madani First implicated in the 15 CCTV photos released by the Turkish police, al-Madani was later found to have been used as a body double for Khashoggi, leaving the Saudi consulate dressed in his clothes on the day the journalist was killed CNN Jamal Khashoggi death: key figures Salah bin Jamal Khashoggi (L) Son of the murdered journalist met with Crown Prince Mohammed bin Salman on 23 October EPA

“In the long run, we need a strong and mature partnership with Saudi Arabia,” Mr Abizaid told the Senate Foreign Relations Committee. “It is in our interests to make sure that the relationship is sound.”

Mr Abizaid, a retired four-star US army general who led US Central Command during the Iraq war, is expected to easily win Senate confirmation.

Mr Khashoggi, a Washington Post columnist and critic of the Riyadh government, was killed at a Saudi consulate in Turkey in October.

His death fuelled simmering discontent in Washington over Saudi Arabia’s human rights record and heavy civilian casualties in Yemen’s civil war, where a Saudi-led coalition is fighting Iran-backed Houthi rebels.

The Senate and House of Representatives have passed resolutions that would end US support for the Saudi-led coalition, an important rebuke of Riyadh. But Mr Abizaid said the Trump administration believes strongly that US support should continue.

“Doing so bolsters the self-defence capabilities of our partners and reduces the risk of harm to civilians,” Mr Abizaid said.

It was also the confirmation hearing for Matthew Tueller, the current US ambassador to Yemen and Mr Trump’s nominee to be ambassador to Iraq. He also defended US support for the coalition.

US politicians have been sharply critical of crown prince bin Salman. Some blame him for Mr Khashoggi’s killing and other human rights abuses.

Eleven suspects have been charged in Saudi Arabia for Mr Khashoggi’s murder and Riyadh has denied the crown prince ordered the killing.

“Saudi Arabia has engaged in acts that are simply not acceptable,” said Republican senator Jim Risch, the committee chairman.

Mr Risch has held two classified briefings in the past two weeks for the panel to discuss Saudi Arabia.

Democrat senator Bob Menendez acknowledged the strategic importance of Saudi ties, amid threats from Iran.

“But we cannot let these interests blind us to our values or to our long term interests in stability,” Mr Menendez said.

He did not mention by name Jared Kushner, the president’s son-in-law who has met with Saudi leaders, rankling some in Congress.

But Mr Menendez asked Mr Abizaid if he would insist on being fully informed about all White House interactions with the Saudis. Mr Abizaid said he would.

As the hearing continued, Republican senator Marco Rubio said crown prince bin Salman had gone “full gangster,” an assertion repeated by another Republican, senator Ron Johnson.

“He is reckless, he’s ruthless, he has a penchant for escalation, for taking high risks, confrontational in his foreign policy approach and I think increasingly willing to test the limits of what he can get away with the United States,” Mr Rubio said.

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Mr Abizaid said in prepared remarks that the Isis has been “nearly vanquished on the ground”, but remains a “potent threat” to the United States and its allies.

While contradicted by some military and intelligence officials, Mr Trump announced in December that he would withdraw all US forces from Syria and has declared that the militant group has been driven out of all its territory.

After criticism, Mr Trump has since decided to leave hundreds of US troops in the country over the longer run.