Chancellor Angela Merkel promised Monday that Germany's government would tackle security issues raised by the Christmas market truck attack and renewed a pledge to make a "national effort" to ensure that failed asylum seekers return home.

The Dec. 19 truck attack in Berlin demanded a swift response that guarantees both security and civil liberties, Merkel said at a conference of civil servants in Cologne.

Merkel, who leads a coalition government of conservative and center-left parties that are traditional rivals, called on officials at federal and local levels to pull together at the beginning of an election year.

Interior Minister Thomas de Maiziere last week proposed a security shake-up that would give the federal government more powers and centralize Germany's domestic intelligence agency. The plan for more central control drew sharp criticism from state governments.

"People don't want us to point fingers at each other," Merkel said during her remarks Monday. "They want better success." The interior minister also has proposed setting up centers to facilitate the deportation of rejected asylum seekers.

Speeding up deportations and voluntary returns of people whose asylum claims are rejected has gained new urgency following the Christmas market attack. Investigators say the truck was driven by a rejected Tunisian whom Germany hadn't managed to deport because Tunisia initially refused to recognize him as its citizen.

"We will work on a national effort to return" people to their homelands, Merkel said. However, she added that "this will only succeed if we negotiate with respect with the countries to which they have to be returned."

"Those who have no residency status must be returned to their homeland, but that also demands of us that we concern ourselves with the problems of these countries and find solutions that are in our mutual interest," Merkel said.

She also pledged to see through a government push to have Tunisia, Algeria and Morocco declared "safe countries of origin," which would speed up the processing of asylum claims by those countries' citizens. So far, the opposition Greens have blocked the move in the German Parliament's upper house.