ROME: Energy ministers from the Group of Eight industrialized countries urged their governments and the rest of the world on Monday to keep investing in new and cleaner energy sources, despite the economic crisis.

Concluding a two-day summit in Rome, G-8 ministers and officials from 15 more countries said governments and businesses must also work to keep energy prices stable or risk hampering the economic recovery.

In a joint declaration, the 23 national delegations urged investments to improve access to energy in poor countries and to develop new technologies to reduce emissions that cause climate change.

"The current financial and economic crisis must not delay investments and programmed energy projects which are essential to economic recovery and sustainable prosperity throughout the world," the declaration said.

U.S. Energy Secretary Steven Chu said the participants had agreed on the need for diversifying energy sources to help keep prices stable and help the economic recovery.

"There's a continued, renewed interest in trying to stabilize energy prices, so that the world economy, both the oil exporting and the oil importing countries, can have a stable future," Chu said at a joint news conference.

Energy prices have seesawed over the last months, plummeting from record highs when the global financial slowdown hit, then rising again at the first signs of economic improvement.

Delegates in Rome also condemned North Korea's reported nuclear test, with the South Korean and Japanese representatives calling on Pyongyang to use nuclear energy for peaceful purposes.

"We are here to create and not destroy," said Italian Industry Minister Claudio Scajola, who chaired the meeting. "With its experiment, North Korea is going in the opposite direction," he said. "We firmly condemn the experimenting and use of nuclear weapons."