Leaders of 20 major developed and emerging economies are expected during a summit in London on April 2 to ensure that their stimulus measures to address the global financial crisis will also lead to the creation of a low-carbon world economy, according to a senior British official.

The Group of 20 leaders are also expected to reaffirm their commitment to advance trade liberalization to ward off protectionism, said Simon Fraser, director general for Europe and Globalization at Britain’s Foreign and Commonwealth Office.

“We must make sure that the actions that we take in dealing with this crisis help to equip us in the long term for a low-carbon, more effective, cleaner global economy going to the future,” Fraser said in a recent interview in Tokyo.

Fraser was referring to a “Green New Deal” to simultaneously address the financial crisis and climate change — a plan to spur green technology investment and generate jobs advocated by U.S. President Barack Obama, U.N. Secretary General Ban Ki Moon and other world leaders.

“If we are pumping money out now as governments, then let’s make sure that that money is going to be used in ways that promote long-term sustainable growth,” Fraser said, urging the G20 to boost spending on environmentally friendly initiatives such as energy efficiency and clean technologies.

Fraser suggested such policy coordination among the group — which represents about 90 percent of the world’s gross domestic product — will spark U.N. negotiations for a new carbon-capping pact to be adopted at key U.N. climate talks in Copenhagen in December. The accord will succeed the Kyoto Protocol, which expires in 2012.

At the London summit, the G20 economies are expected to review fiscal and monetary policy actions they have taken since the first summit last November in Washington and to study whether they are adequate and effective in bolstering the financial system and global growth, Fraser said.

“We need to review the measures that have been taken, make sure that we are coordinating them most effectively to deal with the consequences of the crisis and make sure that the measures taken in one country do not damage the interests of another country, for example,” he said.

Fraser said the leaders are also likely to discuss measures to strengthen the international financial system, such as an improved early warning system and macro financial surveillance by the International Monetary Fund to identify risks in the global economy and enable governments to respond with better coordinated action.

He said the world economy, climate change and development are expected to top the agenda at the July summit of the Group of Eight major nations in Italy.

Development issues include improvement of health, education and sanitation in developing countries, while talks on climate change involve greenhouse gas emissions reduction targets for developed nations and financial support for poor countries to help them reduce emissions and adapt to the impact of global warming, such as rising sea levels, Fraser said.

He called for a review of the role and composition of the G8, saying it is “unreasonable” to expect a group that was created to meet the challenges of the 1970s oil crisis to solve the challenges of the 21st century, given the growing clout of emerging nations in the world economy.

“Many of us have acknowledged that the G8 will need in some way to expand to incorporate the most influential emerging economies, especially China and India,” he said. “The path is inevitable, even if it brings with it risks in diluting the like-mindedness of the group and its internal efficiency.”

The G20 groups the G8 — Britain, Canada, France, Germany, Italy, Japan, Russia and the U.S. — plus Argentina, Australia, Brazil, China, India, Indonesia, Mexico, Saudi Arabia, South Africa, South Korea, Turkey and the EU.