WASHINGTON — The U.S. joined 174 countries at the United Nations in New York City on Friday to sign the historic Paris climate change agreement, a move hailed by more than 100 companies, including Levi Strauss, Adidas, L’Oréal, Gap and Eileen Fisher.

The landmark agreement, reached by world leaders at a summit in Paris known as the COP21 in December, aims to reduce greenhouse gas emissions and curb global warming.

High-ranking officials and world leaders gathered at the U.N. headquarters for the historic signing on Friday, using Earth Day as a marker to drive the message home.

The climate pact is the culmination of years of negotiations at the U.N. and sets a long-term target of reducing global warming to below 2 degrees Celsius.

Countries must now formally approve the agreement through domestic procedures before it can be implemented.

“For sure, the agreement that we reached in Paris is the strongest, most ambitious global climate pact ever negotiated,” said Secretary of State John Kerry, who signed the agreement on behalf of the U.S. “But the power of this agreement is not that it, in and of itself, guarantees that we will actually hold the increase of temperature to the target of 1.5 degrees or 2 degrees centigrade.

“The power is the message that it sends to the marketplace,” Kerry added. “It is the unmistakable signal that innovation, entrepreneurial activity, the allocation of capital, the decisions that governments make, all of this is what we now know definitively is what is going to define the new energy future — a future that is already being defined but even yet to be discovered. The power of this agreement is what it is going to do to unleash the private sector, and it is already doing to set in pace the global economy on a new path for smart, responsible, sustainable development.”

VF Corp., Levis Strauss & Co. and Nike Inc. were among 220 companies that in 2014 endorsed President Obama’s plan proposed by the Environmental Protection Agency to reduce carbon dioxide emissions at power plants in the next 15 years.

Earlier this week, they joined 107 companies in a statement lauding the signing of the agreement and calling for quick action on the EPA’s Clean Power Plan. That initiative was coordinated by the Boston-based non-profit organization Ceres and the World Wildlife Fund.

“Levi Strauss & Co. is proud to stand with 100-plus companies in welcoming the Paris Agreement and supporting a low-carbon economy here in the United States,” said Anna Walker, senior director of global policy and advocacy at Levi Strauss. “We pledge to do our part to address climate change and encourage U.S. lawmakers to do the same.”

All of the signatories pledged “in our own operations and beyond, to realize its vision of a global economy that limits global temperature rise to well below 2 degrees Celsius.

“We want this economy to be energy-efficient and powered by low-carbon energy. We believe there are cost-effective and innovative solutions that can help us achieve these objectives. Failure to build a low-carbon economy could put America’s prosperity at risk. But the right action now would create jobs and boost competitiveness,” the companies said in the statement.

They also called on U.S. leaders to strongly support the “swift implementation” of the EPA’s plan and other low-carbon policies and additional investment in the low-carbon economy in the U.S. and abroad.

In separate news related to Earth Day, Cotton Inc. released new videos and information about sustainability initiatives in the cotton industry, featuring some of the steps the cotton industry has taken over the past 40 years to reduce its environmental impact.

“Earth Day reminds us that the choices we make in our daily lives can help reduce environmental impact,” Cotton Inc. said. “Activities like conserving water and recycling are solid investments in the future of the planet — so is choosing cotton products. U.S. cotton growers have reduced their pesticide applications by 50 percent over the last three decades; and reduced irrigated water applications by 45 percent.”