Switzerland is stepping up border controls a week ahead of the G-8 summit, which will take place on Lake Geneva.
The authorities are concerned about security during anti-globalisation protests scheduled to take place in Geneva at the same time.
The justice ministry said the measures, which will come into force on Thursday, were aimed at preventing known troublemakers from entering Switzerland.
An estimated 100,000 people are expected to take part in protests in western Switzerland to coincide with the summit that opens in the French town of Evian on June 1 and runs until June 3.
"Switzerland will not be sealed off," Lieutenant-colonel Alain Brenneisen told swissinfo.
Nevertheless he said there would be systematic checks of vehicles and luggage, and border police would have the authority to refuse entry to any person considered suspect.
Neighbouring countries have provided a list of 300 names of people with a history of troublemaking and they will be refused entry into Switzerland.
"This is a normal, legal measure," Daniel Dauwalder from the Federal Police Office told swissinfo.
Around 100 soldiers have been deployed to reinforce the border guard but they are not expected to have any contact with people coming or going.
Officials are bracing themselves for tailbacks at border posts and chaos on the roads as many routes in the region will be closed off.
The security measures are expected to stay in place for at least two weeks.
A French army radar system has been installed on the Vevey hillside to monitor the airspace from Lake Geneva to the Rhone valley, said Didier Vallon, Swiss Air Force spokesman for the G-8.
A Swiss farmer gave up a hectare of land to allow French personnel to install and operate the radar system in conjunction with their colleagues on the other side of the lake.
Swiss soldiers will provide security for the site.
Switzerland is bracing itself for mass anti-globalisation protests in Lausanne and Geneva.
Some 10,000 security personnel will be in the region to ensure there are no major disturbances.
Last week, the government agreed to request 1,000 German police reinforcements to help keep order.
swissinfo with agencies
In total 10,000 security personnel will be deployed to ensure there are no major disturbances in Switzerland during the G-8 summit.
The Swiss army has mobilised 5,600 soldiers to reinforce security.
Cantons Vaud, Valais and Geneva have mobilised 2,000 police officers, while other cantons have provided 800 security personnel.
The cantons have requested an additional 700 police officers.
Germany is expected to supply 1,000 police officers.