The Trump administration has angered Senate Republicans after failing to obey a law requiring it to report to Congress its conclusions about who is responsible for the death of Jamal Khashoggi.

A deadline last Friday imposed in 2018 by 22 bipartisan senators was ignored by the White House. The lawmakers had called for an investigation into the killing of the journalist, who was allegedly strangled and dismembered in October inside a Saudi consulate in Istanbul.

The probe, which specifically directed the White House to conclude whether Saudi crown prince Mohammed Bin Salman was responsible for the murder, was requested under the Global Magnitsky Human Rights Accountability Act.

A senior administration official told Politico Donald Trump “maintains his discretion to decline to act on congressional committee requests when appropriate”.

But Marco Rubio, a Republican senator who sits on the committee, said the Trump administration’s failure to meet the deadline “violates the law”.

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

“The law is clear about those timelines. I’m urging them and I expect them to comply with the law,” he added.

Republican senator Cory Gardner said there was “no excuse” and that the government “must submit it”, while Chuck Grassley, an influential Republican lawmaker, said “they better have a good excuse for not issuing it”.

Over the weekend, secretary of state Mike Pompeo pushed back against allegations of a US-backed cover-up over the killing of Khashoggi, who was a prominent critic of the Saudi royal family.

"America is not covering up for a murder," he told reporters at the US embassy in Budapest.

Mr Pompeo sent on Friday a letter to Bob Menendez, the ranking Democrat on the foreign relations committee, in which he said Mr Trump had called for a prompt and open investigation into the death of Khashoggi.

Mr Pompeo wrote that in multiple meetings with Saudi officials and in numerous public statements, he had "emphasised the importance of a thorough, transparent and timely investigation, including accountability for those responsible for the killing".

He also noted the US sanctioned 17 Saudi individuals for their involvement in the killing, but the letter did not assess whether the crown prince was responsible.

Democratic senator Tim Kaine of Virginia, where Mr Khashoggi lived, accused the Trump administration of “aiding in the cover-up of a murder”.

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"The Trump administration has blatantly turned a blind eye to this crime, and is now refusing to provide a required report about who is responsible for his murder, despite the fact that the CIA concluded that Crown Prince Mohammed bin Salman personally ordered Khashoggi's killing,” he said.

Mr Pompeo insisted the US would “continue our investigation” and that Mr Trump had been “very clear” that his administration would “continue to hold all of those responsible accountable”.

The CIA is reported to have assessed with “high confidence” that Mr Bin Salman was involved in the order to kill Mr Khashoggi - a claim he has vehemently denied - partly based on the judgement that as the country’s de facto ruler he would have had to have known.