The first black US president is coming under fire from members of his Democratic Party for naming a stream of white men to key cabinet and leadership posts in his second administration.

President Barack Obama on Thursday named Jack Lew as his Treasury secretary, the fourth white male he has named to the prized cabinet posts in recent weeks.

Lew's nomination follows Obama's pick of Senator John Kerry to replace Hillary Clinton as secretary of state. He has also named former senator Chuck Hagel to be defense secretary and John Brennan to head the Central Intelligence Agency.