Merkel said that the fact that she had chose to keep the border open for refugees was an important and correct decision in an "exceptional humanitarian situation".
Seeking a fourth term, Merkel has had to contend with loud and sustained heckling on her campaign trail from demonstrators strongly opposed to her refugee policies, reported Reuters.
Merkel bristled at the suggestion that her dominant lead in the polls over Social Democrat Martin Schulz renders the election campaign in Europe's largest economy "boring".
Her response to the migrant crisis has inflicted political damage on her party with the right-wing Alternative for Germany (AfD) party expected to win 10% of the vote in September.
Asked about the European Commission's plan announced in May not to continue the controls beyond November, Merkel said she would call for their extension during talks with its chief Jean-Claude Juncker on Wednesday.
Merkel told the German newspaper Bild last week that big bonuses to the auto industry were unfair and that she was angered at the manufacturers' exploitation of law loopholes.
In an interview yesterday, discussing her response to the refugee crisis, the Chancellor said she would do everything "the same way again" if she had the opportunity.
"She is using the infrastructure of the state to fly to her campaign events at a bargain price", Schulz said. This centre would be in Egypt, a transit country for migrants striving to reach Europe.
German challenger Schulz slams Merkel as aloof as campaign heats up
To spread the migrants across the continent, the European Union devised a plan in 2015 to relocate across the bloc about 160,000 asylum seekers who arrived in Italy and Greece, countries that serve as a gateway to Europe and have been overwhelmed by the crisis.
Although the plan has successfully reduced irregular migration flows and came as a significant relief for Merkel in domestic politics, the European Union failed to timely deliver the promised funds.
Angela Merkel says she wants to work more closely with Libya's government to curtail illegal migration from Africa to Europe. The chancellor has already indicated she would not form a coalition with AfD but might take in the Free Democrats.
German Chancellor Angela Merkel is calling on Turkey to release German citizens swept up in the aftermath of a failed coup attempt, calling their imprisonment "unjustified".
29 at a Berlin press conference that she wanted to have better relations with Turkey, but the relationship between Berlin and Ankara was now at "a very complicated phase".
She says "we would like better relations, but that has something to do with the fulfillment of the principles of the rule of law".
"And that means serving the people of Germany", she said.