WASHINGTON (AP) — Senators are criticizing the Trump White House for not allowing its senior cybersecurity adviser to testify before the Armed Services Committee.

At a hearing Thursday, GOP committee chairman John McCain of Arizona said the White House cited executive privilege and longstanding precedent against having staff not confirmed by the Senate appear before congressional oversight panels.

Rob Joyce is President Donald Trump's top cybersecurity adviser. Joyce was appointed to the National Security Council post earlier this year.

McCain says the absence of Joyce underscores "a fundamental misalignment between authority and accountability in our government today when it comes to cyber."

Florida Democratic Sen. Bill Nelson suggested the committee consider issuing a subpoena to compel Joyce's testimony. McCain says he thinks that's an idea worth discussing.