Environment ministers from six of the Group of Seven countries on Monday reaffirmed their countries' commitments to reducing greenhouse gas emissions through the Paris climate agreement—but the U.S. refused to join them.

U.S. Environmental Protection Agency Administrator Scott Pruitt attended the start of the G7 environment meeting, which was held over two days in Bologna, Italy, but he left after only a few hours to return to Washington for a cabinet meeting. Although he left an acting deputy in his seat, Pruitt's early exit was seen as a snub.

On Monday, the ministers issued a communiqué, saying that they "reaffirm strong commitment to the swift and effective implementation of the Paris Agreement, which remains the global instrument for effectively and urgently tackling climate change and adapting to its effects." The document also included a lengthy section on what they see as a critical role of the World Bank and other multilateral development banks (MDBs) in financing efforts to limit rising temperatures and cut greenhouse gas emissions.

In a footnote, the U.S. said it would "not join those sections of the communiqué on climate and MDBs, reflecting our recent announcement to withdraw and immediately cease implementation of the Paris Agreement and associated financial commitments."

The move comes as world leaders express their increasing dismay with President Donald Trump's announcement earlier this month that the U.S. will withdraw from the 2015 Paris climate deal. Since the announcement, leaders from other G7 countries—which include Canada, France, Germany, Italy, Japan, the United Kingdom and the European Union—have strongly denounced the decision.

Last week, the German government issued a "fact check" of Trump's speech, noting its "blatant fallacies."

Germany will preside over another major leadership summit in July, when the G20 meets. And it will host the next formal round of international climate talks in November at the UN's climate headquarters in Bonn, with the tiny island state of Fiji presiding. On Friday, Germany's environment minister, Barbara Hendricks met with California Gov. Jerry Brown, who has been organizing other states and cities to commit to hitting the targets of the climate agreement. Brown last week also met with Chinese President Xi Jinping, attended a clean energy forum and signed green energy agreements with two Chinese cities.

"The unprecedented split on climate change out of the G7 environment ministers' meeting is another clear signal that the rest of the world is forging ahead with the actions needed to meet the climate crisis, despite President Trump's decision to withdraw the U.S. from the Paris climate agreement," said Alden Meyer, director of strategy and policy, Union of Concerned Scientists, in a statement Monday.

"Together with the pledges made by a growing coalition of U.S. mayors, governors, business leaders and others to meet America's Paris commitments without him, the meeting highlights President Trump's increasing isolation on climate and clean energy issues, both at home and abroad," Meyer said.