President Barack Obama is busy assembling his administration's cabinet for his second term in office.

On Thursday, he nominated Jack Lew to replace Treasury Secretary Timothy Geithner. Lew is currently serving as the White House chief of staff.

He is said to be an expert on the federal budget and a tough negotiator. But Some Republicans accuse Lew of not compromising in past battles over fiscal policy.

Lew's nomination is also drawing a different kind of criticism against the Obama administration.

For the first time in years, all the top cabinet posts will be held by men. Some have voiced their opposition to the all-male group.

"Women serve in key policy roles here within the White House, as they do throughout the administration," White House spokesman Jay Carney said in response to the criticism.

Besides Lew, the president has nominated former Sen. Chuck Gagel for defense secretary, Deputy National Security Advisor for Homeland Security John Brennan to the head the CIA, and Sen. John Kerry for secretary of state.