TOKYO (REUTERS) - Japan is aiming to cut greenhouse gases to zero by 2050 and become a carbon-neutral society, Prime Minister Yoshihide Suga said on Monday as he unveiled a major shift in position on climate change.

Japan had previously said it would be carbon neutral as soon as possible in the second half of the century, rather than set an explicit date.

"Responding to climate change is no longer a constraint on economic growth," Suga said in his first policy address to parliament since taking office last month.

"We need to change our thinking to the view that taking assertive measures against climate change will lead to changes in industrial structure and the economy that will bring about great growth."

Japan's target of no greenhouse gases emissions on a net basis by 2050 brings it into line with the European Union, which set a target of being carbon neutral by that same date last year.

Chinese President Xi Jinping in September pledged to make his country "carbon neutral" by 2060.

Japan is the world's fifth-biggest emitter of carbon dioxide, and while steps are being taken to increase renewable energy, it also plans to roll out new coal-burning power stations.

Later, Industry Minister Hiroshi Kajiyama told a news conference that plans for attaining key parts of the goal would be drawn up by the end of the year.

"Carbon neutrality itself is a growth strategy, and we must carry it out with all we have," he added.

To achieve its goals, Suga said new solar cells and carbon recycling would be key, and Japan would intensify research and development in those areas, along with digitalising society - a policy he has pushed since taking over from Shinzo Abe.

The announcement was cheered by policy makers and investors.

"Japan joining the EU in targeting carbon neutrality by 2050 is very welcome, and so is PM Suga's focus on green technologies and especially solar, as a growth driver," said Eric Pedersen, Nordea Asset Management's head of responsible investment.

But he also warned that Japan would need to start decommissioning coal power and stop building and financing new coal power abroad.

His announcement was welcomed by Ms Christiana Figueres, former executive secretary of the UN Framework Convention on Climate Change, who congratulated Mr Suga in a message on Twitter, adding: "True leadership on the #RacetoZero".

In a nod to Japan's deep economic ties with giant neighbour China, Suga said a stable bilateral relationship was essential - but also said that Japan would maintain contact with "all like-minded nations for a free and open Indo-Pacific".

Suga last week made his first visit to Vietnam and Indonesia, part of Japan's efforts to strengthen ties with Southeast Asian countries as a counter to China's growing push to assert claims over disputed East China Sea isles.

Pressure has been building from below with the number of cities, towns and villages aiming for carbon neutrality by 2050 increasing to 163 from 4 in a little over a year, according to the environment ministry.

Still, there are plenty of vested interests to stymie the efforts including from the old power utilities, car and steel makers, along with industrial companies that use coal boilers to produce steam needed for manufacturing purposes, all of whom have plenty of lobbying power.

Companies running smaller, older coal plants are already lobbying the government heavily for exemptions to the plans shut to them down, an official at one of Japan's trading houses that supplies them with fuel told Reuters last week.

But Japan's most powerful business federation, known as Keidanren, is now advocating the 2050 target with its chairman Hiroaki Nakanishi pushing the line at the prime minister's economic advisory council, according to minutes from the Oct 6 meeting.

A report released in August showed how Keidanren is dominated by energy-intensive sectors representing less than 10 per cent of the economy, resulting in national policies that favour coal and hindering efforts on climate change.

Mr Suga initially was buoyed by strong support, but a poll conducted by the Nikkei and TV Tokyo at the weekend said approval had fallen by 11 points to 63 per cent since a poll after he took office a month ago.

Disapproval rose by 9 points to 26 per cent, partly due to limited easing of international travel restrictions along with his rejection of six scholars for membership in a science advisory panel, raising concern about academic freedom, the Nikkei said.