In a Los Angeles Times op-ed, Whitman called Trump’s behavior “indefensible” and said that he should rename his “America First” platform “Russia First.”

“My Republican colleagues … have to end their willful ignorance of the damage Trump is doing both domestically and internationally,” she wrote. “We must put aside the GOP label, as hard as that may be, and demonstrate the leadership our country needs by calling on the president to step down.”

Whitman, who also served as former President George W. Bush’s EPA administrator, has been highly critical of Trump’s actions at his press conference with Russian President Vladimir Putin.