Chinese President Hu Jintao has called for a crackdown on graft and extravagance in the military, kicking off a campaign to bring discipline to the world's largest army, state press said Monday.

In a recent circular he ordered the end to "prominent problems" in the military and reiterated the need to maintain a clean and honest defence force, the People's Liberation Army Daily reported.

"Faced with a severe and complex ideological struggle, senior and mid-level officers must maintain staunch ideological conviction and resolutely uphold political steadfastness," the paper quoted the order as saying.

Military officers must do more to follow orders, obey the law, end lax work habits and maintain Communist Party discipline, it said.

The circular was aimed at ending "luxury and hedonism" in the 2.3-million-strong military, the China Daily said.

"The public impression is that some army officers have lavish lifestyles," said Mao Shoulong, a researcher at People's University in Beijing, according to the paper.

"Army corruption is mainly caused by a relatively weak prevention network," he said, adding that the military remains largely not transparent on matters of internal graft.

The circular comes after China's parliament announced in March a 480.7 billion yuan (69 billion dollar) defence budget for 2009, a 14.9 percent increase over the previous year.

Following annual double-digit growth in defence spending over most of the last 20 yars, China's rapidly modernising military has kept pace with the nation's rising political and economic clout.

The United States, Japan and their allies have repeatedly expressed concern about China's military build-up and what they see as a lack of transparency about the intent behind the expansion.