WASHINGTON -- The White House is releasing financial disclosure reports that show President Barack Obama and first lady Michelle Obama had assets worth between $1.8 million and $7 million last year. The range in amounts is little changed from the previous year's holdings.

The forms are required by law but permit public officials to list their assets in broad ranges. As a result, a precise net worth is difficult to ascertain.

The forms show the largest jointly owned assets by the president and the first lady were Treasury notes worth between $1 million and $5 million.

Vice-President Joe Biden reported 2013 assets of between $276,000 and $940,000, including a rental property owned jointly with his wife, Jill, in Wilmington, Delaware.