"The U.K. and Japan both recognize the importance of investing in a diverse and clean energy mix in order to ensure a competitive economy, long-term security of supply and avoid dangerous climate change," British Secretary of State for Energy and Climate Change Ed Davey said in a statement.
Davey hosted Japanese Prime Minister Shinzo Abe, who is spending two days in the country on a state visit.
The British government said it reviewed with the Japanese prime minister ways to advance a low-carbon economy, adding nuclear power was a key component of a greener future.
Japan started taking on more natural gas to meet its energy demands in the wake of the 2011 meltdown at the Fukushima Daiichi nuclear power plant.
Japanese conglomerate Marubeni Corp. started work last month on a solar power facility situated on land spoiled by the 2011 tsunami that sparked the meltdown. Billed as the largest facility of its kind for the region, the company said the plant's capacity of 28.3 megawatts is enough to meet the annual electricity demands of 8,000 households.