ESSEN, Germany — To loud applause, Chancellor Angela Merkel told her party members on Tuesday that Germany should ban full-face veils “wherever legally possible” and that it would not tolerate any application of Shariah law over German justice.

Accepting her party’s nomination as its candidate for another four-year term, the chancellor used the moment to broaden her stance on banning the veil, trying to deflect challenges from far-right forces that have made some of their deepest gains since World War II.

In welcoming nearly one million asylum seekers to Germany a year ago, Ms. Merkel emerged as a powerful voice for tolerance across a Europe gripped by anxiety over waves of arriving migrants and fears of terrorism.

Now, as anti-immigrant parties have advanced at the expense of mainstream parties, including her own, Ms. Merkel tried a tricky balancing act between holding fast to Western values and tilting farther right to avoid being outflanked by populist challengers.