Recordings of former U.S. President Joe Biden’s conversations with his literary co-author, Mark Zwonitzer, show that in some of the discussions Biden experienced brief memory lapses, despite discussing foreign policy issues in detail, Bloomberg reported.

In the conversations, he also allowed himself to speak candidly in criticizing his former running mate and the country’s vice president, Barack Obama.

In one conversation in April 2017, speaking about the Obama administration’s reluctance to impose sanctions on China, Biden said:

“Between you and me, Obama always came to the right decision, but a day later and a dollar short.”

At the same time, Biden added that he was not sure he himself could have acted more quickly if he had been in the post of U.S. president.

“Perhaps if I had been president, I might not have had the courage to do it either,” he said.

According to the agency’s sources, the recordings were made as part of work on Biden’s memoirs. In the conversations, he also spoke in detail about international politics, but some fragments reportedly contain moments when he struggled to recall certain details or events.

Biden served as U.S. vice president under Obama from 2009 to 2017, and then became the country’s 46th president in 2021.