A new nuclear energy deal between the U.S. and Brazil got lost in the shuffle this week, as the White House sought instead to play up a pledge between the two countries to increase renewable energy.

Nevertheless, the two countries did also agree to collaborate on nuclear energy development as part of a broad plan to address global warming agreed to earlier this week in Washington.

The new agreement between the two nations comes as nations prepare for international negotiations on climate change later this year in Paris, in which Obama wants Brazil's support to reduce emissions from fossil fuels.

It is likely nuclear energy will have to be part of any emission reduction strategy, but it was unclear why the administration was so coy in discussing it in announcing the new cooperation.

Nuclear energy has received more scrutiny after the 2011 Fukushima Daiichi power plant disaster in Japan, which caused many countries to reconsider their commitments to nuclear power. Obama has said that nuclear is part of his all-of-the-above energy strategy, but has emphasized the importance of safety moving forward.

The administration has also placed a lot of stock in developing smaller, modular nuclear reactors that integrate new safety features.

But much has changed since Fukushima. And many analysts and proponents believe that achieving the dual goals of integrating more renewables and reducing emissions will need an ample supply of nuclear power to achieve.

Nuclear energy, unlike coal and natural gas, emits no carbon dioxide emissions, while producing a reliable stream of energy that can offset the intermittency of wind and solar.

Nuclear energy provides what utilities call baseload electricity, meaning it can produce power 24-hours a day, 7-days a week with minimal interruptions. Wind and solar electricity cannot do this, yet. These forms of renewable energy are limited by how long the sun shines and how often the wind is blowing. Therefore, some kind of baseload power will be needed to fill in the gaps in electricity production created by renewables.

The U.S.-Brazil agreement, under the heading of clean energy cooperation, includes nuclear energy as a low-carbon resource, while emphasizing the need for it to be safe and sustainable.

"Nuclear Power Generation: Benefiting from the shared successful experiences of both countries, Brazil and the United States will cooperate on safe and sustainable nuclear power generation and technologies," a joint communiqué between the two countries reads.

The U.S. nuclear industry hopes the joint agreement will allow for new business and trade opportunities between the two countries. Daniel Lipman, the Nuclear Energy Institute's vice president for international programs, said the trade group "welcomes this development as it allows for deepening [of] … industrial relationships" between the two countries.

"Hopefully this will lead to more opportunities to develop new business for our respective industries," Lipman told the Washington Examiner in an email.

But what was emphasized from the meeting between President Obama and his Brazilian counterpart, Dilma Rousseff, was a pledge to double and triple renewable energy by 2030, leaving out questions about the need for baseload power.

Brian Deese, the president's climate adviser, emphasized the renewable energy aspects of the agreement in a conference call with reporters ahead of the meeting. Most news coverage of the climate pledge only emphasized the renewable energy target. The president didn't any other aspect of the agreement in his public remarks -- only making mention of the solar and wind goals.

The goal aims to have 20 percent of all electricity in the U.S. and Brazil coming from renewable resources in the next 15 years, excluding hydro-electric power. The communique also listed collaboration on financing those resources as a priority.

The pledge between the two countries was primarily meant to underscore their commitment to reach a global deal later this year in Paris to reduce greenhouse gas emissions from fossil fuels.

"The Presidents expressed their commitment to work with each other and with other partners to resolve potential obstacles towards an ambitious and balanced Paris Agreement," the joint U.S.-Brazil communiqué stated. The agreement will be forged under the auspices of the United Nations in late November in Paris, where countries will negotiate how far they are willing to go to cut carbon emissions. Many scientists say carbon dioxide emission are causing manmade climate change, resulting in more severe weather, droughts and wildfires.

But Lipman suggests that the ties between the U.S. and Brazil run deeper on nuclear energy than the relatively short experience the two have in collaborating on renewables.

"For decades U.S. companies have been cooperating [with Brazil] on new plants, fuel and operating plant services, including major equipment modifications," Lipman said. "The Brazilian nuclear industry is a mature one with an excellent operating record and includes a world class supply chain."

The two countries also announced the creation of a joint working group that will meet in October to discuss further cooperation on renewables, nuclear energy and other aspects of their climate change agreement.