WASHINGTON — President Donald Trump's attorney Rudy Giuliani argued on Sunday that the president has broad constitutional powers as it relates to the special counsel investigation into Russian interference in the 2016 presidential campaign, including the authority to end the investigation or even pardon himself.

But Giuliani said that the president was unlikely to do either because both would be a path to impeachment.

"You might want to say he has very broad powers and somebody who wants to question that under Article Two has a big, big burden of showing that there is no innocent explanation for what he did," Giuliani said on NBC's "Meet the Press" on Sunday. "They just can't do that. So I would like to convince them to exercise some, you know, constitutional restraint here."

Giuliani's comments represented an extension of a legal argument outlined in a 20-page memo leaked to the press over the weekend that Trump's legal team sent to special counsel Robert Mueller.

He said Trump could put an end to the investigation all together, saying "it sure looks" like that is within the president's constitutional authority.

As for potentially pardoning himself, Giuliani said he can legally do so: "Nothing limits the presidential pardon."

But he added the president wouldn't do it because of the repercussions. "The president of the United States pardoning himself would just be unthinkable. And it would lead to probably an immediate impeachment," he said. "President Trump has no need to do that. He didn’t do anything wrong."

Giuliani said the only check on the president is Congress. And he argued there was no reason for the president to exercise such powers on the issue of obstruction because "we can win it on the facts."

Trump's team are still negotiating the terms of a potential interview with Mueller. Giuliani, the latest attorney added to Trump's legal team, said he doesn't think the president should sit for an interview but that Trump wants to.

He said he'd advise Trump to testify only if they agree to a "narrow" set of conditions and if the special counsel's office has an "open mind."