Washington (CNN) -- German Chancellor Angela Merkel joined U.S. President Barack Obama on Tuesday in saying Libyan leader Moammar Gadhafi must step down, expressing support for the NATO military mission even though her country abstained from the U.N. Security Council vote that authorized it. At a joint news conference at the White House, Merkel said Germany's participation in NATO operations shows its support for the Libya mission. She also noted that Germany has increased resources to the U.S.-led mission in Afghanistan to free other countries to contribute to the Libya mission. "It is our joint will that this NATO mission is successful," Merkel said of the Libya operation, adding that what happens in North Africa affects Europe. "Those are our immediate neighbors, and we have a choice. Either this works out well, or we have an enormous refugee problem. and so it's not only out of charity ... there's not only a moral obligation, but we have also a vested interest in seeing to it that this continent, this region comes on its feet."
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NEW: Obama bestows nation's highest civilian honor on Merkel
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Obama warns of possible new sanctions against Iran
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"I trust her," Obama says of the visiting German chancellor
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The two leaders emphasize cooperation rather than policy differences
Obama also referenced his unique status as America's first African-American president, as well as Merkel's as @placeholder's first female chancellor.
On the economic front, @placeholder continues to expand its trade surplus with record exports, causing critics to complain it should boost domestic consumption to ease the imbalance as part of global efforts to quicken recovery from the recession.