BERN, Switzerland — Secretary of State Mike Pompeo is on a weeklong trip to Europe where he is raising sensitive issues with national leaders — from Iranian missiles to Chinese technology to the economic collapse of Venezuela — but the most colorful conversations could take place this weekend out of public earshot in a secretive conclave at a Swiss lakeside resort.

In Montreux, on the eastern shore of Lake Geneva, political and business leaders from Western nations are gathering for the 67th Bilderberg Meeting, an annual forum in which participants agree not to reveal exactly what was said or who said it. It is a shadow version of Davos, the elite annual winter conference in the Swiss Alps that President Trump has attended once but has also criticized.

The State Department has not even put the Bilderberg Meeting on Mr. Pompeo’s public schedule, though a senior official confirmed he was attending Saturday.

Mr. Pompeo landed in Zurich on Friday afternoon after a morning of meetings with German leaders in Berlin, then took a helicopter to Bern, where he spoke at a gathering of department employees at the United States Embassy. Mr. Pompeo was traveling with his wife, Susan.