in an investigation of the Obama Admin's Spygate/Russiagate scandals. The visits were overseas.
“Mr. Durham is gathering information from numerous sources, including a number of foreign countries. At Attorney General Barr’s request, the President has contacted other countries to ask them to introduce the Attorney General and Mr. Durham to appropriate officials.”
https://dailycaller.com/2019/09/30/barr-john-durham-investigate-cia-fbi-trump/
The foreign nations include Ukraine, Italy, Great Brittan, Australia and Malta.