"It is difficult today to end the state of emergency," Valls told BBC television as France marked exactly one year since the November 13, 2015 jihadist attacks that left 130 people dead.
"Especially since we are going to begin a presidential campaign in a few weeks with meetings, with public gatherings. So we must also protect our democracy," Valls added in the interview with the BBC's HARDtalk programme.
"Besides, this state of emergency device allows us to make arrests, administrative checks which are effective... So yes, we are probably going to live a few months more with this state of emergency."
The state of emergency was introduced on the night of the Paris attacks and extended for six months in late July.
While stressing he remained "very cautious", Valls said the risk of similar coordinated attacks appeared to have diminished.
"But we may face attacks of the kind that we saw in Nice," he said, referring to the July attack in the Riviera resort in which a 31-year-old Tunisian mowed down 86 people in a truck. "That's to say some individuals who are driven directly by the internet, by social networks, by the Islamic Sate group, without having to go to Syria or Iraq."
Meanwhile, on the separate subject of a possible renegotiation of the 2003 Le Touquet accords which extend the British border to Calais' ferry ports, Valls made a plea for cooperation.
"We can always change a treaty, but if tomorrow we were saying that there was no agreement, that there was no longer a treaty, and that the border was open, there would be thousands and thousands of people who would converge on Britain, that would be a drama in the Channel and a major problem for Britain," he said. "That really shows that we need cooperation."
The comments come after France last month demolished the notorious Jungle migrant camp in Calais, where thousands of people had been living in squalid conditions hoping to stow away on trucks headed to Britain.
Under the Le Touquet agreement, Britain pays millions of euros each year for security in Calais but it is French police and border agents who are on the frontline.
Many French politicians believe London has simply outsourced a problem to France and the agreement should be torn up. The leading candidates hoping to represent the right in next year's race for the French presidency have called for the Le Touquet deal to be renegotiated, with frontrunner Alain Juppe calling last month for the British border to be shifted back across the Channel.