Chancellor Angela Merkel on Saturday asked voters to keep her in office for four more years and enable her to ensure Germany remains a "country that is respected in Europe and defends its rights in the world."

In her last big campaign rally ahead of Sunday's election, Merkel touted her administration's successes and pledged her continued commitment to Europe, although she said Germany's solidarity with its neighbors will always come "with conditions."

The euro zone debt crisis has not yet been overcome and the region's countries must continue with the reforms that Germany carried out in its day, she said.

"Neither Eurobonds nor debt mutualization," she said in remarks in Berlin to supporters of her center-right Christian Democratic Union party, which leads voter-preference surveys.

The CDU's top rival, the center-left Social Democratic Party, or SPD, has criticized Merkel's austerity-first approach to bringing down southern European governments' high debt and deficit levels.

Merkel's party is looking to secure a big enough margin of victory and thereby avoid having to enter into a grand coalition with the SPD.

Germany, she recalled, was for many years "Europe's sick patient," but it made unpopular changes, such as raising the retirement age to 67, that strengthened the country's finances and paved the way for today's "collective success."

The goal is for Europe to follow this path and become a strong continent because "Germany will only do well if Europe is doing well," Merkel, who is seeking a third term in office, said.

The chancellor also ruled out the possibility of a tax hike amid calls by her opponents to raise levies on the highest wage earners.