U.S. Democratic presidential contender Joe Biden on Saturday said there would be “no legal basis” for Republicans to subpoena his testimony in President Donald Trump’s impeachment trial, clarifying remarks from Friday that drew criticism.

“I want to clarify something I said yesterday. In my 40 years in public life, I have always complied with a lawful order and in my eight years as VP, my office — unlike Donald Trump and Mike Pence — cooperated with legitimate congressional oversight requests,” Biden said on Twitter.

“But I am just not going to pretend that there is any legal basis for Republican subpoenas for my testimony in the impeachment trial,” Biden added.