WASHINGTON - Hillary Clinton will soon release her 2015 tax returns.

A source close to the Democratic presidential nominee says she will release them in "the coming days." Her running mate, Sen. Tim Kaine and his wife, Anne Houlton, will also release the last 10 years of their returns. The source spoke on condition of anonymity Thursday to discuss the plans in advance.

Clinton has hit Republican nominee Donald Trump for not releasing his returns. Trump has said he won't release them until after an IRS audit is complete.

The Clinton campaign has put out eight years of Clinton's returns, from 2007 to 2014. Combined with releases during her previous campaigns and her husband's time in office, the Clintons have made their tax returns public since 1977.