Next month's G8 summit of wealthy nations should push oil producing nations to increase supply, Prime Minister Gordon Brown said on Monday following talks with visiting Japanese Prime Minister Yasuo Fukuda.

Brown also told Fukuda there should be a global carbon trading system aimed at cutting world emissions of greenhouse gases which he hoped Japan would join, Japanese officials said.

"We agreed it would be important for G8 members to press oil-producing nations to do all they can to increase production and investment to increase future supply," Brown told reporters after the meeting in London.

Brown said the two leaders had agreed on the need to move away from dependence on carbon fuels, including by increasing investment in nuclear power and improving energy efficiency.

Both leaders have faced domestic criticism over fuel taxes as consumers feel the pinch from soaring food and fuel prices.

Commodity inflation is one of the top agenda items in Fukuda's round of meetings with European leaders ahead of the summit, which he will host on the island of Hokkaido next month.

Fukuda is also hoping to make progress on reaching a consensus on international climate change policy.

A gathering of G8 environment ministers in Japan last month, agreed global emissions should be halved by 2050, a target last year's G8 summit agreed to "consider seriously".

Brown added his voice to that of German Chancellor Angela Merkel, who in a meeting on Sunday urged Fukuda to have Japan join a global carbon trading market, Japanese officials said.

But the issue of a compulsory cap-and-trade mechanism is controversial in Japan, where it is opposed by powerful businesses.

"The topic of carbon trading is still under wide-ranging debate in Japan," officials quoted Fukuda as telling Brown, adding that it was important for major developing country emitters such as India and China to be involved in a system.

Fukuda met Merkel on Sunday and plans to meet French President Nicholas Sarkozy and Italian Prime Minister Silvio Berlusconi on the sidelines of the UN-backed food summit in Rome this week.