President Trump speaks at an April 5 news conference with Jordan’s King Abdullah II in the White House Rose Garden. (Nicholas Kamm/Agence France-Presse via Getty Images)

An arm of Congress is launching an investigation into President Trump’s transition operation, including its public spending, private fundraising and how it managed communications with foreign governments.

In a letter dated April 5, the independent, nonpartisan Government Accountability Office (GAO) told Sen. Elizabeth Warren (D-Mass.) and Rep. Elijah E. Cummings (D-Md.) that it would undertake the probe.

The investigation will focus on four major areas of interest, a GAO official wrote: federal ethics guidelines that governed Trump’s transition; the financial operation behind the effort, including expenditures by the government; conflicts of interest and financial-disclosure rules; and how the transition arranged phone calls and other contact with heads of foreign governments.

“As discussed with your staff on Feb. 27, 2017, we plan to complete our work and send a draft product to the agencies for comment in June 2017,” wrote a GAO official, whose name was redacted before Warren’s office posted the letter online this week.

Warren and Cummings had asked the GAO to review the transition’s practices in late November, citing rising concerns about conflicts of interest between Trump’s about-to-be leadership of the government and his private business activities.

“Mr. Trump’s conflicts of interest raise questions about the taxpayer-funded expenditures associated with the transition,” the lawmakers wrote to the GAO, adding: “There is no transparency with regard to transition expenditures, raising additional questions about how taxpayer funds may be flowing into Mr. Trump’s pockets.”

The GAO’s letter was first reported by the Associated Press.