Chinese President Hu Jintao's visit to Japan was a "complete success", Foreign Minister Yang Jiechi said on Sunday, in a further sign of the warming relations between the traditional rivals.

"President Hu Jintao's warm spring visit opened up a new phase for China-Japan strategic and mutually beneficial relations, and was a complete success," Yang said in a statement posted on China's foreign ministry website.

Hu's five-day visit -- only the second ever by a Chinese head of state to Japan -- ended on Saturday and saw both sides commit to closer ties, although there were sporadic protests over Beijing's rule of Tibet.

"Both sides confirmed that China and Japan are cooperation partners, with neither side posing any threat to the other, and that they will support each other's peaceful development," Yang said.

On Wednesday, Hu and Japanese Prime Minister Yasuo Fukuda agreed to start regular summits to ease decades of tension coloured by Japan's past militarism.

The two sides also agreed to push forward full cooperation in finance, information, trade, investments, small and medium-sized enterprises and intellectual property protection, Yang said.

They also pledged joint efforts to maintain peace and stability in Northeast Asia, Yang said, and agreed to strengthen cooperation in climate change and environmental protection.

Despite the optimism, progress in resolving specific disputes seemed slow, including over lucrative gas fields in the East China Sea.

China's clampdown in Tibet also overshadowed Hu's visit, with thousands of protesters demonstrating in Tokyo on his arrival Tuesday.

The new spirit of friendship between Beijing and Tokyo makes a stark contrast to the atmosphere just a few years ago.

China broke off high-level dialogue with Japan during the 2001-2006 premiership of Junichiro Koizumi, citing his insistence on visiting a shrine that venerates Japanese war dead including war criminals.