Spot-checks introduced in September 2024 will now be in force until at least mid-September 2026, having already been twice extended, ministry spokesman Leonard Kaminski said.
“Local authorities are still overwhelmed,” he said. “We have to do more here so that we get to a situation that is sustainable for our country, for our society.”
Under the Schengen Agreement covering most of western and central Europe, border checks are supposed to have been abolished with limited exceptions for emergencies.
Along with several other nations, including neighbours such as Poland and Austria, Germany has reintroduced some checks, citing a threat to order and security from uncontrolled migration.
The last government under Social Democratic Chancellor Olaf Scholz began checks after a series of deadly attacks carried out by foreign nationals shook Germany.
Since taking office in May, a coalition led by conservative Chancellor Friedrich Merz has deployed more police at the borders in a bid to turn back greater numbers.
“An overhaul of migration policy has begun, but we haven’t reached the end of the road,” Kaminski said.
“I cannot give you a specific figure in terms of reductions, but quite simply, there needs to be order when it comes to migration policy,” he added.
In December, Merz had said he expected the measures to end following joint EU action to better police the bloc’s external borders.
Germany has not backed down from the checks despite a court ruling in June that the government broke the law when it sent back three Somalian asylum seekers to Poland without considering their claim.
Between mid-September last year and the end of January, almost 50,000 people were sent back as a result of the checks, Kaminski said.
Merz has cracked down on migration since taking power last year, instituting the controls, deporting some convicted criminals to Afghanistan and making it harder for family members outside Germany to join refugees inside the country.
The anti-migration Alternative for Germany (AfD) party is about level with Merz’s conservative CDU in most polls.