The quarantine requirement will be imposed due to increases in new infections.
“Since mid-June, the new coronavirus has experienced an upsurge in Switzerland after infected people entered the country from Schengen and non-Schengen states” beyond Europe's open borders zone, said the government.
“Consequently, from July 6, anyone crossing the border from certain regions must quarantine themselves for 10 days,” the Federal Council said.
The list of countries will be published on Thursday. The Swiss government promised to regularly monitor the situation in other countries while updating the list frequently.
While the names of the countries have not yet been provided, Swiss President Simonetta Sommaruga indicated that Serbia and Kosovo would be included.
Health Minister Alain Berset implied on Wednesday that Sweden may also be included.
Swiss media reported on Wednesday that a number of new infections had been imported among a group of men who arrived from Serbia.
Affected people will be informed on planes, coaches and at the borders, and must register with the local authorities once in Switzerland.
Switzerland stopped short of imposing strict confinement when it introduced measures in mid-March aimed at stopping the spread of the new coronavirus.
It began gradually easing its restrictions on April 27th, with a fourth stage on June 22nd lifting the maximum limit on gatherings to 1,000.
Switzerland has its own SwissCovid contract-tracing smartphone app, using Bluetooth wireless technology.
It has been downloaded nearly a million times, with 928,909 signing up in the first six days since it came out.
While the EU will lift entry restrictions from July 15 on travellers from 15 countries deemed to have the virus under control (including Japan, South Korea, Australia and Canada), Switzerland will do likewise on July 20 — with the exception of Serbia.