Justice Minister Morgan Johansson told Radio Sweden it is because of the security situation, including risk of terrorist attacks, and he thinks most people understand the importance.
"We have ongoing security issues," Johansson said, citing last year's truck attack in Stockholm and the nation's elevated terrorism threat level as examples. "I think we need a better control on how people are moving across the borders."
If extended, border controls will continue until mid-November of this year.
EU member states in Europe's Schengen passport-free zone can institute border controls for security reasons. The EU Commission can issue an opinion about the checks but cannot stop the decision when it is linked to security.