The 50th edition of the meeting sees the return of Trump after he pulled out in 2019.
Fighter jets, ground defence systems and additional radar, among other measures, will protect some 3,000 participants at the meeting, Swiss police officials said on Monday.
“Various people in the world are under great threat, if you can put it that way, and wherever they appear, they deserve commensurate security measures,” Walter Schlegel, the regional police commander, told a news conference on Monday.
“The U.S. president has a big security detail that must be deployed,” Schlegel said.
Trump is expected to attend on Tuesday and Wednesday, as hearings get under way in the U.S. Senate, where lawmakers are set to decide whether he should be removed from office.
Activists are set to reach Davos by hiking trails and by train after authorities banned foot traffic on a road leading to Davos from the neighbouring village of Klosters.
To start their three-day march on Sunday, some protesters wore koala bear costumes to call attention to Australian bush fires whose destructive intensity has been linked by scientists to a warming planet.
Don't believe Han Solo's evasion of Empire TIE Fighters. There are many miles of vacuum space between each asteroid in a field.