Chancellor Friedrich Merz's conservatives won February's national election on a promise to bring down immigration levels, which opinion polls showed many voters regarded as being out of control, although numbers have been falling for over a year.
In an interview with the Welt am Sonntag newspaper published on Saturday, Interior Minister Alexander Dobrindt said the approach of using third countries could work only if there was a Europe-wide consensus.
"We need third countries that are prepared to take migrants who are objectively unable to return to their home countries," he told the newspaper, Reuters reported.
Earlier this month, the EU's executive Commission proposed a scheme that would let member states reject asylum applications from migrants who passed through a "safe" third country on their way to the bloc. The proposals, criticized by rights groups, have yet to be adopted by national governments or the European Parliament.
"No individual EU member state can create this model on its own: it will have to happen on an EU level," Dobrindt said. "We are preparing the foundations for that right now."
Dobrindt's initial promises to tighten border controls on taking office angered neighbors who protested at plans to return to their territory those migrants found not to have a right to enter Germany.
An Italian plan to process asylum seekers picked up at sea in Albania has stalled amid Italian court challenges.
A scheme by Britain, which is not an EU member, under its previous Conservative government to send asylum seekers who arrived in Britain without permission to Rwanda was scrapped by Prime Minister Keir Starmer when he took office last year.