(WASHINGTON) — A day after his formal nomination, Mark Esper, President Donald Trump’s nominee to be the next secretary of Defense, will face questions from senators at his confirmation hearing. Esper, who’s served as Trump’s Army secretary, became acting Defense secretary on June 24 after his acting predecessor, Patrick Shanahan, withdrew his name from nomination following reports of domestic violence in his family’s past.He will appear before the Senate Armed Services Committee on Tuesday morning, more than 200 days after former defense secretary James Mattis resigned over policy differences with the president.During Esper’s confirmation process, he cannot serve in his “acting” role, so Navy Secretary Richard Spencer assumed the duties of acting defense secretary on Monday afternoon when the White House submitted Esper’s formal nomination to the Senate. During this time, Esper will return to serving as Army secretary.”While my time in this role is anticipated to be brief, I am fully prepared and committed to serve as Acting Secretary of Defense, and I will provide continuity in the leadership of the Department,” Spencer said in a letter to Defense Department personnel. “Our allies and partners can rest assured that the Department of Defense remains ready to respond to meet our commitments around the globe in support of our common goals.”Esper’s confirmation hearing on Tuesday is not expected to be contentious, but senior defense officials have stressed that they are not presuming his confirmation.”It’s up to the Senate to take as long as they need, but there’s historical precedent for under a week,” Eric Chewning, chief of staff to the acting Defense secretary, told reporters last week.One issue that could be raised by senators on Tuesday is Esper’s time as chief lobbyist for the defense company Raytheon.In a letter to Esper last week, Sen. Elizabeth Warren, D-Mass., said that she was “concerned by the cozy relationship between giant defense contractors, the DoD and the White House” and that Esper’s ethics agreement was insufficient.Asked about Warren’s criticism on Monday, Chewning said that Esper “is doing everything required by law” and that his ethics agreement will be updated from his time as Army secretary, if confirmed by the Senate. He also has a “screening arrangement” currently in place that dictates how staff handle any issues that could present a conflict of interest, Chewning said.Esper graduated from West Point in 1986 — the same class as Secretary of State Mike Pompeo — and went on to serve in the Army for over a decade, including a deployment to the Middle East during the Gulf War.Before joining Raytheon, he spent a considerable amount of time on Capitol Hill as a Senate committee staffer and adviser to several senators. He was also the deputy assistant secretary of Defense for negotiations policy during the Bush administration.As Army secretary, Esper spent time with the president, traveling with him to an Abrams tank factory in Ohio and to the southern border amidst the deployment of active duty soldiers there.Esper stepped into his role as acting defense secretary as the Trump administration was considering how to navigate increased tensions with Iran. And in late June, he attended a NATO defense ministerial in Brussels, urging U.S. allies to confront Iran.His confirmation hearing comes as a number of top Pentagon jobs have yet to be permanently filled, including the deputy defense secretary, chief management officer and Air Force secretary.Copyright © 2019, ABC Radio. All rights reserved.