Sen. Marco Rubio (R-Fla) and four other Republican senators sent a letter to President Trump imploring him to end nuclear energy talks with Saudi Arabia. (J. Scott Applewhite/AP)

Five Republican senators sent a letter to President Trump on Wednesday imploring him to end ongoing discussions with Saudi Arabia on nuclear energy cooperation in the wake of Washington Post contributing columnist Jamal Khashoggi’s killing at the Saudi Consulate in Istanbul.

The senators also threatened in the letter to file legislation to block any civil nuclear agreements with Saudi Arabia if Trump will not agree to suspend negotiations “for the foreseeable future.”

“We already held serious reservations about negotiations for such an agreement,” Sens. Marco Rubio (R-Fla.), Todd C. Young (R-Ind.), Cory Gardner (R-Colo.), Rand Paul (R-Ky.) and Dean Heller (R-Nev.) wrote in the letter, first reported by NBC.

“The ongoing revelations about the murder of Saudi journalist Jamal Khashoggi, as well as certain Saudi actions related to Yemen and Lebanon, have raised further serious concerns about the transparency, accountability, and judgment of current decision-makers in Saudi Arabia.”

Congressional dissatisfaction with the U.S.-Saudi relationship was on a slow ascent before the prominent journalist’s disappearance in early October. But his apparent slaying — which most lawmakers believe occurred at the behest of Saudi leaders, including Crown Prince Mohammed bin Salman — has precipitated unprecedented calls for consequences, including sanctions and an end to arms sales and military support for the Saudi kingdom in its controversial regional engagements, particularly in Yemen’s civil war.

Saudi officials have acknowledged that Khashoggi, a self-exiled critic of the Saudi government, was killed in the consulate, but they deny that the action had their authorization.

The senators’ letter indicates yet another layer of distrust in Saudi leaders: concern that the kingdom may try to adapt nuclear technologies acquired in a civil-use deal for weapon-making purposes.

Saudi Arabia has never agreed to terms that would prohibit it from turning a civil nuclear program dedicated for energy production into a tool to enrich uranium, reprocess plutonium and pursue other weapons-grade uses “that can bring a nation within weeks of producing a nuclear weapon,” they said, pointing out that the United Arab Emirates did accept such terms for a similar deal.

The senators suggested that it would be hypocritical and dangerous for the United States to accept anything less than a Saudi pledge to abide by terms of an Emirates-style deal — terms known as the “Gold Standard” — especially when the administration is demanding such behavior from Iran.

“Given your Administration’s ongoing efforts to press the Iranian regime — in the words of Secretary of State Mike Pompeo — to ‘stop enrichment and never pursue plutonium reprocessing,’ we have long believed that it is therefore critical and necessary for the Kingdom of Saudi Arabia to accept and uphold this ‘Gold Standard’ for responsible nuclear behavior,” the senators said.