BRUSSELS (AP) — European Union leaders have failed to back a plan to make the bloc's economy carbon neutral by 2050 in spite of promises to fight harder against climate change.

Ahead of a U.N. meeting in the fall, the proposal was relegated to a non-binding footnote in the final statement of Thursday's summit of EU leaders in Brussels.

"For a large majority of Member States, climate neutrality must be achieved by 2050," the footnote read.

However, for the change in approach to become an official target, all 28 EU countries need to back the change.

According to several officials who spoke anonymously as they were not authorized to speak publicly, 24 countries including Britain, France and Germany supported the initiative, but were held back by Poland and a few other nations which heavily depend on a fossil-fuel economy.

Environmental group Greenpeace said European leaders blew the chance to agree a deal and called on the EU to organize an emergency meeting before the U.N. summit in New York in September.

"This is a black day for climate protection in Europe," said Greenpeace spokesman Stefan Krug. "A small number of eastern European countries prevented Europe's impasse on climate protection from being broken."

"The climate strikes by tens of thousands of students and the election choices of millions of Europeans for more climate protection were ignored," he said.

The protests are part of the 'Fridays for Future' rallies that have been held regularly across Europe for almost a year and which urge political leaders to act more decisively against global warming.

Krug said that not only did EU members fail to set a concrete target for 2050, he noted that the bloc's old goal for 2030 remains in place even though it was agreed before the Paris climate accord four years ago.

EU officials said there still was time to swing the eastern nations around.

French President Emmanuel Macron, who two years ago launched the "One Planet Summit" aimed at speeding up the implementation of the 2015 Paris climate agreement, vowed to continue the fight within the EU and at the next G20 summit.

Frank Jordans in Berlin contributed to this report.