German investor confidence has risen for the second consecutive month amid growing optimism the country can meet a series of challenges, including the arrival of some 1 million asylum seekers.

The ZEW institute said Tuesday its confidence index rose to 16.1 points in December from 10.4 in November. Economists had predicted a more modest rise to 15.

ZEW head Clemens Fuest says the survey of 223 financial analysts shows that confidence over the German economy, Europe's biggest, is "sufficiently robust" to meet the challenges in the coming year.

ING-DiBa economist Carsten Brzeski says domestic demand has become an important growth driver, so that despite "the Greek crisis, the Chinese slowdown, the refugee influx and increased geopolitical tensions the Germany economy has continued its solid growth."