Merkel says she will serve full four-year term if re-elected

A full fourth term would extend her chancellorship to 16 years through to 2021.

Presenting a ten-point-plan for a modern Germany and a better Europe, Schulz said he would introduce an investment obligation for the state to boost public spending on infrastructure and education.

In the wide ranging interview, Merkel said she hoped to work with North Atlantic Treaty Organisation to resolve a widening gulf between Turkey and Germany.

The chancellor rejected calls to limit the number of people allowed to ente Germany. She said the two issues were completely unrelated.

"It's important to me that the citizens have a true choice", Merkel said.

"For many people, including myself, something changed when we saw the Britons want to leave, when we were anxious about the outcome of the elections in France and the Netherlands", Merkel told voters, some of whom wore straw hats with black-red-and-gold hatbands, the colors of the German flag.

She distanced herself from local politicians within her conservative party who had called for Hamburg's mayor Olaf Scholz, a senior SPD member, to step down because of the riots. "For this, I have the same responsibility as Olaf Scholz does - and I'm not dodging", she added.

Schulz, a Social Democrat whose party has been Merkel's coalition partner for the past four years, pledged on Sunday to guarantee that surplus revenue would go toward spending on infrastructure if he wins the Chancellery on September 24.

Merkel said Germany had to increase investment in high-speed internet broadband connections.

"At this point we can't spend the money that we have", Merkel said in an interview with ARD television on Sunday.

Germany has been criticized internationally for a lack of domestic spending.

French President Emmanuel Macron said in an interview published Thursday that Germany had to move on investment.

Germany's current-account surplus has been on the receiving end of persistent criticism, including most recently from the International Monetary Fund and the administration of U.S. President Donald Trump.

Polls ahead of the September election show Merkel in a position of strength.