BEIJING — China’s government said Tuesday it still is a developing country despite becoming the second-largest economy, reflecting its reluctance to take on new obligations on climate change and other issues.

Beijing needs to improve life for millions of impoverished Chinese, said a Commerce Ministry spokesman, Yao Jian. It was the government’s first public reaction to news Monday that China had passed Japan in economic output during the April-to-June quarter, confirming its arrival as a global commercial power.

“China is a developing country,” Yao said. “The quality of China’s economic development still needs to be raised. It needs more effort to improve economic quality and people’s lives.”

Rapid growth has boosted the communist government’s political and economic influence abroad. But Beijing has resisted adopting binding limits on greenhouse gas emissions or making commitments in other areas such as easing controversial currency controls or guaranteeing foreign suppliers equal treatment in government purchasing.

China overtook Japan on Monday when Tokyo reported a quarterly gross domestic product of $1.286 trillion, behind China’s $1.335 trillion reported earlier.

With a population of 1.3 billion, China ranks among the poorest countries per person, with an average income of $3,600 last year, compared with Japan’s $37,800.

China’s government is in the midst of a marathon effort to spread prosperity from its thriving eastern cities to the poor countryside and west. Communist leaders are trying to diffuse tensions over a huge wealth gap between an elite who have benefited the most from three decades of reform and the poor majority.

China has more than 40 million people living below its official poverty line, Yao said.

China’s rapid growth has produced striking contradictions. It has the world’s second-largest military budget and has launched two manned space missions, but many families live on a few thousand dollars a year.