"Everything is on the table," Engel said, when asked whether the probe will include the reportedly close relationship between Kushner and Saudi Crown Prince Mohammed bin Salman.

The New York Times on Sunday reported that Kushner, President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE's son-in-law, offered advice to Crown Prince Mohammed about how to “weather the storm” after Khashoggi's death.

The two reportedly continued to message back and forth as Khashoggi's death sparked an international diplomatic crisis.

Khashoggi was killed in the kingdom's Istanbul Consulate in early October. Lawmakers are gearing up for a heated battle over U.S.-Saudi relations.

The CIA has concluded that bin Salman ordered Khashoggi's assassination, though Trump has not backed the U.S. intelligence agency's findings.

Multiple senators, including some who typically side with Trump, emerged from a briefing about Khashoggi's murder saying that they feel the evidence conclusively ties the crown prince to Khashoggi's slaying.

Khashoggi was a Washington Post contributing columnist and Virginia resident.

Trump has continued to emphasize the financial and diplomatic ties between Washington and Riyadh, in particular the multimillion-dollar arms deal from the U.S., as he downplays the crown prince's involvement.

The Senate could break with Trump this week with a vote on a resolution aimed at ending U.S. support for the Saudi-led military campaign in Yemen.