WARSAW, Poland — A project to develop small nuclear power reactors in Poland is moving forward, with Polish energy giant Orlen and two U.S. government financial institutions signing an agreement Monday.

Poland is turning toward energy that is renewable or does not use climate-changing fossil fuels as it tries to break its reliance on coal. Moscow's invasion of Ukraine also has accelerated Poland's drive to cut its dependence on Russian oil and natural gas .

In a ceremony at the U.S. ambassador’s residence in Warsaw, the U.S. Export-Import Bank and U.S. International Development Finance Corporation signed letters of interest to lend up to $3 billion and up to $1 billion, respectively, to the Orlen Synthos Green Energy project. It's aims is to develop some 20 small BWRX-300 modular reactors designed by GE Hitachi Nuclear Energy.

U.S. Ambassador Mark Brzezinski stressed that Russia's aggression against Ukraine almost 14 months ago reinforced the need to turn toward safe and reliable energy sources.

Later, Polish Prime Minister Mateusz Morawiecki said at a news conference that the country needed a “cheap, clean and reliable energy source” like the small nuclear reactors that will produce emission-free energy and be a driving force for the economy for decades to come.

Coal mining is among Poland's largest employers, providing some 80,000 jobs and supplying some 70% of the country's energy, and Morawiecki said the industry will continue to guarantee power security. He stressed, however, that global climate concerns and European Union regulations are calling for a shift to renewable and clean energy, which the nuclear reactors plan is helping advance.

Orlen CEO Daniel Obajtek told The Associated Press that only nuclear power can guarantee energy security and keep the lights on when the wind isn't blowing or sun isn't shining.

He said the support of the U.S. financial institutions “shows the credibility of the process" of developing nuclear energy.

It comes after Germany shut down its last three nuclear power plants this past weekend as it transitions to renewable energy like wind and solar, which has drawn skepticism at home and abroad.

Poland’s first BWRX-300 reactor should launch in 2029 and will be the world’s second, after a similar one opens in Darlington, Canada.

Synthos Green Energy owner and Polish billionaire Michal Solowow, Obajtek’s business partner in the project, calls it a “energy revolution” for the country, ironically brought about by its poor climate record.

“From the condition it is in today — meaning the worse energy mix that we have in the EU — Poland can turn within the next 20 years into a leader,” Solowow told the AP. “This bad situation we are in today is offering us a chance to make intensive investments and move into a totally new dimention."

Last year, Orlen drew criticism for expanding and acquiring Polish fuels company Lotos and gas giant PGNiG under one label, making it the biggest energy operation in Central and Eastern Europe. It also has a refinery in Lithuania and fuel stations in Germany, the Czech Republic and Slovakia.

Obajtek defended the move, saying it gave the company greater potential and resilience in changing or unfavorable economic conditions.

The company plans to expand further, Obajtek said, but refused to divulge the details.

He said at a news conference earlier that “there is no stopping of energy transformation” and that the oil and gas giant — 49.9% owned by the Polish state — is planning 320 billion zlotys ($75 billion) of investments.

That money will go to both offshore and more onshore renewable energy as well as to advanced fuel technologies, including biofuels, he said in an interview.

In February, Poland's government and the U.S. Westinghouse Electric Company signed a deal for pre-design cooperation on the central European nation’s first large nuclear power plant, using the American company’s technology. Construction is to begin in 2026, and it aims to start supplying the energy grid in 2032.