Germany's newly elected leader went to Capitol Hill Tuesday to mark the 20th anniversary of the fall of the Berlin Wall and to urge lawmakers to reach an agreement on climate change.

"We have no time to lose," Chancellor Angela Merkel said. "Today's generation needs to prove that it is able to meet the challenges of the 21st century, and that, in a sense, we are able to tear down walls of today."

However, Merkel acknowledged that no deal would be successful without the support of China and India.

She also expressed gratitude for American support throughout the process leading up to German reunification.

She praised the U.S. military who brought aid and supplies to West Berlin. She also thanked the millions of American troops and diplomats stationed in Germany between the end of the war and today.

"Overcoming the division of Europe would simply not have been possible," without their help, she said.

Monday marks 20 years since the Berlin Wall was pulled down, leading to the reunification of Germany. Merkel is the first German chancellor in 50 years to address the U.S. Congress since Konrad Adenauer in 1957.

She's the first German chancellor ever to appear in front of a joint session of Congress.