WASHINGTON – "There is a towel here. Are you going to give me drugs?"

Jamal Khashoggi uttered those words minutes before he was gruesomely murdered inside a Saudi consulate in Turkey last fall.

“We will anesthetize you,” came the response from Khashoggi's killers, according to a damning report released Wednesday by a top U.N. human rights expert.

That report contained explosive new details documenting "credible evidence" that high-level officials in Saudi Arabia – including the kingdom's crown prince and de facto ruler, Mohammad Bin Salman – were involved in the death of Khashoggi, a Washington Post columnist and U.S. resident.

The response from President Donald Trump's administration so far? Silence.

Lawmakers and foreign policy experts said they don't expect the United Nation's investigation to alter the Trump administration's close alliance with the kingdom, or prompt the White House to dig any deeper into to the crown prince's role in the incident.

The White House declined to offer any comment on the U.N. report, referring questions to the State Department. A State Department spokesperson did not answer specific questions but said agency officials were reviewing the U.N. report.

"The U.S. position on this so far has been impervious to international public opinion," said Natan Sachs, director of the Center for Middle East Policy at the Brookings Institution, a left-leaning think tank in Washington. The administration has made the U.S.-Saudi alliance a cornerstone of its Middle East foreign policy, he said, and has not shown any willingness to re-evaluate that.

Sachs noted that the U.N. report landed months after American lawmakers, the CIA and the international community had already reached a similar conclusion about Mohammad Bin Salman's involvement.

"I think he’s complicit to the highest level possible,” Sen. Lindsey Graham, R-S.C., told reporters in December after a CIA briefing on Khashoggi's murder.

The U.N. reports provides new details, including snippets of conversation between Khashoggi and his Saudi killers. And Agnes Callamard, the U.N. special rapporteur who led the independent inquiry, urged the United States to take concrete steps in response to her conclusions. Among her requests to the U.S. government:

Open an FBI investigation into Khashoggi's murder and pursue criminal prosecutions in the U.S. for those responsible

Make an official determination about the crown prince's culpability in the matter

Declassify, to the "greatest extent possible," all materials related to Khashoggi's murder.

Sachs and others said there's almost no chance Trump will take such action.

"The president is trying to resist any accountability for them," said Sen. Tim Kaine, a Democrat from Virginia, where Khashoggi lived before his death. "They’ve decided they’re turning a blind eye to every instance of Saudi atrocities."

Khashoggi was a Saudi citizen who had grown increasingly critical of the Saudi government; fearing for his safety, he moved to U.S. and became a permanent resident. He went to the Saudi consulate in Turkey on Oct. 2 to get some routine documents he needed to marry his fiancee and never emerged. His body has yet to be found.

Kaine and others said that while they do not expect the Trump administration to rebuke the kingdom or the crown prince, they do think the U.N. report will increase support in Congress for a re-examination of the U.S.-Saudi alliance.

The White House sanctioned 17 Saudis it said were involved in Khashoggi's death but Trump has resisted taking stronger actions.

Even before Wednesday's report, lawmakers in both parties launched an effort to block the president from selling $8.1 billion in weapons to the Saudis, the United Arab Emirates and Jordan.

Sen. Robert Menendez, D-N.J., said U.N. report will "fuel" fresh support for that effort. The Senate could vote to bar those sales this week, and a similar House effort is also gaining steam.

But lawmakers would need a two-thirds super majority in both chambers to overturn Trump's presumed veto of such legislation, and it's not clear if supporters can hit that high threshold.

Whether the U.N. report will spark any change inside the Saudi royal family is another question. Saudi government officials have blamed "rogue" agents for Khashoggi's killing, and they slammed Wednesday's U.N. report.

Saudi Arabia's foreign affairs minister, Adel al-Jubeir, said the report contained "unfounded allegations" that undermine its credibility. He said the Saudi judicial system is handling the case appropriately.

"The Kingdom's leadership has conducted the necessary investigations, which have led to the arrest of a number of persons accused of the case, ongoing investigations and ongoing trials," he said in a tweet Wednesday.

Sachs said the U.N. report "could heighten tensions within the royal family and within the elite more broadly." He emphasized that the internal machinations of the Saudi family were almost impossible to discern from the outside.

But, he said, "the crown prince is playing a very high risk game," and there's always danger of a coup or other challenge to the crown prince's grip on power.

Kaine said Saudi insiders have told him to keep the pressure on the kingdom.

"What I’m hearing from inside the country is Congress should keep pressing" for change, he said.

Contributing: David Jackson