Germany's vice chancellor on Friday blasted what he described as irresponsible bickering in Chancellor Angela Merkel's conservative bloc over the migrant crisis.

Bavaria's Christian Social Union, part of Merkel's Union bloc but often an awkward ally, has publicly criticized Merkel's approach for weeks. Party leader and Bavarian governor Horst Seehofer this week demanded moves from the national government by Sunday to limit the migrant influx, saying that otherwise he would have to consider "what options we have."

Merkel has argued there's no way to instantly stop the flow of newcomers. She has stuck to a positive message, insisting that "we will manage" the influx.

Vice Chancellor Sigmar Gabriel, a center-left Social Democrat, said the infighting "would appear bizarre in normal times." He told the Spiegel Online news portal: "In view of the great challenge for our country from the high immigration of refugees, the argument ... is now threatening the government's ability to act."

"This kind of mutual blackmail and invective is unworthy and simply irresponsible," Gabriel said, arguing that "it is further unsettling people and fears that we won't manage it are rising."

Merkel, Seehofer and Gabriel are to meet Sunday. The national government, a coalition of Germany's biggest parties, already has passed legislation meant to make it easier to integrate people who win asylum and to send home those who are rejected.

Still, Bavaria in particular still faces a relentless flow of newcomers. All of Germany's border with Austria, through which the main migrant route runs, is in the southeastern state.

Germany is a preferred destination for migrants and has seen more arrivals than any other European Union country. About 577,000 people seeking asylum came to Germany from January to the end of September this year, authorities say.