“We show our face in interpersonal communication,” Ms. Merkel told delegates of her Christian Democratic Union party to some of the strongest applause of her more than hourlong speech. “Because of this, the full veil is unacceptable for us. It should be banned wherever legally possible.”

Ms. Merkel also said that German law superseded Islamic law, or Shariah, in a nod to criticism that her policy of accepting refugees had undermined the rule of law in the country. Some 890,000 asylum seekers arrived in Germany last year, largely from Muslim countries, as Ms. Merkel refused to close the country’s borders to refugees.

Ms. Merkel’s tougher rhetoric doesn’t necessarily herald a change in policy. In September, she said that a ban on burqas would be appropriate in certain situations such as in courtrooms or the civil service, but wearing the veil was generally protected by the constitutional guarantee of freedom of religion.