Jay Sekulow said the answers were in response to "issues regarding the Russia-related topics of the inquiry."
Trump told reporters earlier Tuesday that he finished answering the questions Monday.
"The lawyers have them. I assume they'll turn them in today or soon," he said as he prepared to depart for his Mar-a-Lago resort in Palm Beach, Fla.
Trump's lawyers said he should only answer questions about accusations of Russian meddling in the 2016 U.S. presidential election, not about allegations he sought to obstruct the investigation by firing FBI Director James Comey.
It's the first time Trump has agreed to give answers since Mueller first asked for a face-to-face interview nearly one year ago. It's unclear whether the special counsel team will further press for that sit-down.
"Look, we made an agreement with them that we'd agree to disagree about that," Trump's lawyer, Rudy Giuliani told The Washington Post. "They said, in good faith, they'd go over our questions and decide if there was still a need for one. We said, in good faith, we'd listen to them, but would be very much inclined against it."