WASHINGTON (AP) — Ratcheting up his attack on Sen. John McCain, GOP presidential candidate Donald Trump said McCain has abandoned the nation’s veterans and made America “less safe” through his votes in Congress.

In an opinion pieced published Monday in USA Today, Trump also lashed out at his fellow GOP presidential hopefuls who have criticized his remarks, calling them “failed politicians.” Trump said he did not need “to be lectured by any of them.”

The op-ed comes as Trump is on the defensive for dismissing McCain’s reputation as a war hero because McCain was captured in Vietnam and “I like people who weren’t captured.”

On a contentious appearance on the “Today” Show Monday, Trump took issue with the media’s reporting on his comments about McCain’s war record, made at a conservative forum in Iowa.