But even as President Biden tried to downplay concerns about his mental acuity, he had yet another misstep: Referring to the President of Egypt as the President of Mexico.

"I think that, as you know, initially, the President of Mexico, el-Sisi, did not want to open up the gate to allow humanitarian material to get in," he said, referring to the border between Egypt and Gaza.

I cringed when I heard him say that, but it is exactly the sort of slip of the tongue I make all the time: I know exactly what I mean, but the wrong word comes out of my mouth. This week, I was talking about oxygen and alveoli but said areolae. No, no, stupid brain. Lungs, not breasts.

Anyway, from context, he obviously meant Egypt when he said Mexico because he was referencing the Hamas/Israeli war and was referring to the border with Israel and opening it up. It isn't in the linked article, but Biden continued as follows:

I talked to him. I convinced him to open the gate. I talked to Bibi to open the gate on the Israeli side. I’ve been pushing really hard, really hard, to get humanitarian assistance into Gaza. There are a lot of innocent people who are starving. There are a lot of innocent people who are in trouble and dying. And it’s got to stop.

So I don't doubt that Biden meant Egypt, but it was unfortunate timing that he'd say the wrong country in a conference questioning his memory.