BERLIN (AP) — German Chancellor Angela Merkel took aim Tuesday at U.S. President Donald Trump's decision to withdraw from the Paris accord, calling the move "very regrettable" at a time when the overwhelming majority of countries worldwide are trying to limit global warming.

"We know climate change isn't a matter of faith," she told an international climate meeting in Berlin. "It's a fact."

Trump announced last year that the U.S. will pull out of the accord negotiated by his predecessor unless he can "get a better deal."

Merkel said Germany remains committed to the Paris climate accord fighting global warming but acknowledged that the country still needs to do more to curb emissions, particularly in the transport sector, if it wants to meet its own goals.

The long-time German leader urged the 178 countries that have ratified the 2015 Paris accord to agree by the end of the year on a rulebook for its implementation.

"The German government stands fully behind the Paris climate accord, because ambitious climate policies don't just help limit the worst consequences of climate change , they also offer chances for innovation and therefore growth and prosperity worldwide," she said.

Germany, the strongest economy in the 28-nation European Union, was once a leader in the fight against climate change but has fallen behind in recent years. Officials predict that Germany will miss its goal of cutting emissions by 2020 by a wide margin.

"We in Germany have to admit that we need to get better," said Merkel, adding that the biggest worry was the country's transport sector, which has seen emissions rise slightly compared to 1990.

The talks in Berlin, attended by ministers from some 30 countries, are part of a series of meetings preparing for December's global climate summit in Poland.

Mateusz Morawiecki, Poland's prime minister, told ministers that the summit's host city of Katowice, a former center of heavy industry and coal mining, would be a showcase for the economic shift that is needed to prevent climate change.