WASHINGTON (Reuters): The United States and Japan will announce a joint partnership to accelerate the emerging field of nuclear fusion, two sources briefed on the agreement said on Wednesday.

The partnership will be announced on Wednesday during a summit at the White House with Japanese Prime Minister Fumio Kishida, the sources said.

Scientists, governments, and companies have been trying for decades to harness fusion, the nuclear reaction that powers the sun, to provide carbon-free electricity. It can be replicated on Earth with heat and pressure using lasers or magnets to fuse two light atoms into a denser one, releasing large amounts of energy.

Unlike plants that run on fission, or splitting atoms, commercial fusion plants, if ever built, would not produce little long-lasting radioactive waste.

The two countries will also agree to support sustainable aviation fuel in a statement from the summit, the sources said.