April 25 (Reuters) - The White House wants to defund a bipartisan board that advises the president and Congress on Social Security policy, two sources familiar with the matter told Reuters, as the Trump administration moves to cut costs and eliminate independent voices in government.

The White House's Office of Management and Budget has notified staff at the Social Security Advisory Board that it plans to cut the board's annual budget from around $3 million to zero, according to the sources, who spoke on condition of anonymity to discuss non-public budgetary details.

Congress established it in the 1990s as an independent federal agency to provide objective analysis on how to improve Social Security, the popular program that annually pays $1.4 trillion in benefits to 73 million Americans.

While the board does not have decision-making power, its research has helped shape how the SSA runs itself and facilitated legislation. It has also played a role in important policy debates, including a 2005 effort under then-President George W. Bush to privatize the agency that ultimately failed.