Former CIA chief John Brennan on Thursday criticized President Trump’s decision to name White House physician Adm. Ronny Jackson to lead the Department of Veterans’ Affairs (VA).

In a tweet, Brennan said that while he personally knows Jackson and can vouch for his skill as a doctor, he thinks Jackson is unqualified to lead the massive agency, the second biggest in federal government.

Trump announced his pick of Jackson on Thursday in the same tweet declaring the ouster of VA Secretary David Shulkin, who had been dogged by accusations of travel abuses.