'There is an upper limit to a country's integration ability,' said vice-chancellor Sigmar Gabriel
German vice-chancellor Sigmar Gabriel said in an interview on Saturday that Chancellor Angela Merkel's conservatives had "underestimated" the challenge of migrant influx.
Gabriel is the leader of the Social Democrats (SPD) -- the junior coalition partner in Merkel's government -- and his comments come as campaigning begins for a federal election next year and regional elections in Berlin and the eastern state of Mecklenburg-Vorpommern.
Hundreds of thousands of migrants from West Asia, Africa and elsewhere flocked to Germany last year. There is an increasing concern about integrating the migrant population into the German society and the labour market.
"I, we always said that it's inconceivable for Germany to take in a million people every year," Gabriel said in an interview with broadcaster ZDF.
"There is an upper limit to a country's integration ability," he added at a news conference on Sunday.
Gabriel also criticised Merkel's catchphrase "Wir schaffen das" ("We can do this"), which she used at a news conference this July after a string of attacks on civilians. Two of the attacks have been claimed by the Islamic State.
Rejecting Gabriel's criticism, Merkel said she was open to changes in the EU's planned quota system which aims to transfer of about 160,000 asylum seekers from Greece and Italy to other EU states. However, she added it was important to work hard with state and municipal authorities and also share responsibility.
It would not be acceptable, Merkel said, for governments to say: "We don't generally want to have Muslims in our country."
(WION with inputs from Reuters)