The French move, announced by the DGAC civil aviation authority, follows similar action by Britain, and notably impacts Europe's two busiest hubs: Heathrow and Charles de Gaulle.
Combined, an average 2.5 million passengers use those two airports each day.
French and British authorities urged passengers to allow extra time to get past the additional measures, which were not specified but were believed to focus on footwear and electronic items such as mobile phones and computers.
US officials on Wednesday publicly demanded enhanced security for airports in Europe and the Middle East which have direct US flights. They did not say whether they had intelligence about a specific plot, but their actions suggested alarm.
The request was "based on real-time intelligence," according to a Homeland Security Department official who spoke on condition of anonymity.
On Thursday, the US embassy in Uganda warned of a possible plot targeting Entebbe airport serving the capital Kampala for later that day. But the danger period elapsed without incident.
AFP