France will reinstate border controls for one month from Nov. 30 to boost security during the U.N. Conference on Climate Change in Paris. The announcement was made Friday by Interior Minister Bernard Cazeneuve on local news network BFM television.

Nearly 200 nations are expected to meet in Paris from Nov. 30-Dec. 11 to work toward a deal to fight global warming in the years from 2020. About 80 world leaders are due in the French capital on the first day of the summit. Authorities expect at least 40,000 people for the conference, the Associated Press reported. The number will be in addition to the tens of thousands of activists from across the globe.

The move was a precaution "because of the terrorist threat or risk of public disorder,” Cazeneuve said, according to the BBC.  However, he reportedly did not mention how stringent the border controls would be or how checks would be carried out.

The European Union's so-called Schengen zone of countries that has open borders, where passport checks are minimal or non-existent, does allow for occasional reintroduction of internal border checks.

France has been on high security alert since the January attack on satirical newspaper Charlie Hebdo and a kosher grocery in Paris. Following the incident, the country has seen several other smaller attacks or attempts, including when a heavily armed suspected Islamic radical was prevented by young American passengers from attacking a Paris-bound high-speed train in August.