Former Secretary of State Condoleezza Rice praised current Secretary of State Rex Tillerson in an interview that aired Sunday on CNN, saying it is “exceedingly difficult” to do his job when he doesn’t know when President Donald Trump will tweet policy.

“And the relationship with the President, it’s hard. But I think what’s hard is to get up every day and not know what the President said at 3 o’clock in the morning, that would be exceedingly difficult,” Rice said on “Fareed Zakaria, GPS.” “But I think Rex Tillerson, in an unusual administration with an unusual President, who has never been in government before, is really doing a very good job on the diplomacy and just putting his head down and going about that work. And under these circumstances, I think that’s the best thing to do.”

Tillerson has had reported difficulties in his relationship with Trump. In October 2017, it was reported that Tillerson called the President a “moron.” It also has been reported that Trump has considered replacing Tillerson and that the effort was meant to “publicly shame” him. He has said he intends to remain in his position.

Rice, who held the position under former President George W. Bush, praised Tillerson for his work with North Korea and Russia and said he’s “doing the work of diplomacy daily.”