President Trump responded on Twitter on Tuesday night to reports that he had an undisclosed meeting with Russian President Vladimir Putin during the G-20 meeting, saying the story is “sick.”

Trump spoke privately for about an hour with Putin during a dinner attended by G-20 leaders and their spouses on July 7. The encounter was not reported at the time and didn’t come to light until today.

Trump and Putin met earlier that day for about two hours in a meeting that was widely publicized.

“All G 20 leaders and spouses were invited by the Chancellor of Germany,” Trump tweeted Tuesday night about the dinner, during which he left his seat to speak to Putin.