The Justice Department moved Friday to officially back President Trump in his quest to prevent the release of his tax returns, Reuters reported.

The Supreme Court filing from Solicitor General Noel Francisco came a week after the president’s personal attorneys moved to appeal a decision from the US Court of Appeals for the Second Circuit, which said Trump had to release the information earlier this month.

The demand for Trump’s taxes “may subject the president to highly burdensome demands for information” and “raises the risk that prosecutors could use subpoenas to harass the president as a result of opposition to his policies,” Francisco said, according to the wire service.

Manhattan prosecutor Cyrus Vance, a Democrat, wants to unseal eight years of Trump’s tax returns as part of a broader criminal inquiry into the Trump Organization and family’s real estate holdings.

During the 2016 presidential campaign, Trump repeatedly promised to release his tax returns after the completion of an audit by the IRS. It is unclear whether the president is still under audit.