Pretty much the standard line for a diplomatic meeting. It is so common with Bush, Obama, and, I guess Trump now, that after the meeting everyone says that everyone else is lying about what they talked about and what was said.
At least a part of the actual negotiation takes place in press releases, as one party and the other release "their version" of the agreements to see who will balk first.
If Trump said, "Yes. Mexico agreed to build and pay for a wall on their Northern border similar to the one they have already built on their Southern border."
That statement could be half truth, half lie, half commentary, half intimidation, and half bluff, all at the same time. We will never know what was really said. We never do.
