Chancellor Angela Merkel's center-left deputy is accusing her conservatives of being too slow to respond to the migrant crisis following a state election in which a nationalist, anti-immigration party beat Merkel's party into third place.

Vice Chancellor Sigmar Gabriel's Social Democrats won Sunday's election in Mecklenburg-Western Pomerania, where Merkel has her parliamentary constituency. It was the first of five regional votes before a national election expected next September.

The three-year-old Alternative for Germany drew supporters from across the spectrum to finish second with 20.8 percent of votes. Merkel's welcome for refugees a year ago was a prominent issue.

Merkel has insisted that "we will manage" the crisis. Gabriel said Monday that "we have to do it too" and that "we have wasted a great deal of time with unnecessary arguments."