German Chancellor Angela Merkel | Sean Gallup/Getty Images Angela Merkel: refugee policy misunderstood, not mistaken The AfD is on its way to the Bundestag, while the CDU will lose influence in Germany's upper house.

BERLIN — Angela Merkel responded to her Christian Democrats' (CDU) serious setback in Berlin state elections by acknowledging shortcomings in how she communicated her refugee policy — but not in the policy itself.

In Sunday's election, both Merkel's CDU and the Social Democrats (SPD), Germany's second-largest party, plummeted, while the anti-immigrant Alternative for Germany (AfD) made huge gains. Founded only three years ago, the AfD now has seats in 10 of the 16 German state assemblies. It took over 14 percent of votes cast in the capital.

The chancellor stood by her decision a year ago to let hundreds of thousands of asylum seekers, many fleeing the war in Syria, into German — a policy that has put the AfD on course to enter the Bundestag, or lower house of parliament, in next year's national election.

"If one of the reasons for the bad performance of the CDU is that the direction, aim and the underlying conviction of our refugee policy were not sufficiently explained to some people, I would like to put more effort into this," Merkel said in a press conference on Monday.

"The reasons [for Sunday's election setback] lie in state politics, but not exclusively," said the CDU leader. "I am the head of this party, and I certainly don't evade responsibility."

Merkel, whose support is taking a battering ahead of next year's election, has also renounced her year-old mantra "We can do it" — her defiant response to those who doubted the country could cope with the influx of refugees, which continued until a few weeks ago.

"The sentence is part of my political work, it's the expression of its stance and its aim," Merkel said. "Much has been interpreted into this … sentence. So much that I hardly want to repeat it," she said, adding that it had been widely misunderstood and turned into an "empty phrase."

"The discussion around it has become an ever-more-unproductive loop. Some felt provoked by the sentence, and I never intended that," she said.

The CDU has come under constant criticism since the refugee crisis began from its more conservative Bavarian sister party, the Christian Social Union (CSU). Members of Merkel's party blame the CSU for the CDU's election setbacks in Berlin and earlier this month in the northeastern state of Mecklenburg-Vorpommern, where Merkel has her constituency.

"[CSU chief Horst Seehofer] left no stone unturned in trying to run the CDU down," said Karl-Georg Wellmann, a CDU lawmaker in the Bundestag, on German radio Monday.

The CDU looks likely to be excluded from power-sharing in the Berlin state assembly, where the SPD will need two other partners — probably the Greens and far-left Linke — to govern the capital. More seriously, the result will diminish CDU's already limited influence in the Bundesrat, or upper house of the German parliament, where the federal states are represented.

Speaking about the rise of the AfD, Merkel said on Monday she felt unable to deploy facts against the far-right party's appeal to insecurity and angst.

"I, myself, would like to respond to it with a feeling I have," she said, using uncharacteristically emotional language. "I have the feeling we will emerge from these complicated times stronger than before… Who, if not us, should be capable of making something good out of this?"

British Prime Minister Theresa May on Monday spoke out against "uncontrolled migration."

Speaking before the U.N. General Assembly in New York, May said: "I think that uncontrolled migration is not in the interests of the migrants themselves, it's not in the interests of refugees — who may find that they see less support as a result — it's not in the interests of the countries that people are coming from, traveling through or trying to get to."