A Chinese man has been detained by Japanese police for breaking into a US naval base in Japan, the Chinese embassy in Tokyo confirmed on Monday, adding it was seeking more details and would provide consular assistance to him.

"We confirm that a Chinese citizen, suspected of violating Japanese laws, was arrested by local police in Yokosuka," the embassy said in a statement on its website. "On learning of the event, the Embassy of the People's Republic of China in Japan dispatched consular officials to visit the man, to obtain more information from him."

Japan's Kyodo News identified the man as Song Dongtao, a 24-year-old sailor from China's Fujian Province. He wandered onto the US naval base in Yokosuka at around 11:20 am on Sunday and was later spotted by US soldiers and transferred to Japanese local police.

Song said he arrived in Nagasaki port 10 days ago and was not willing to return to China. He then took a trolley to Yokosuka, Kanagawa Prefecture, and planned to join the US naval forces, the news agency said.

Japanese police said that Song violated the US-Japan Status of Forces Agreement (SOFA) and that the investigation of Song's motives is ongoing.

The SOFA has become a major political issue between Tokyo and Washington following cases of violent crimes committed by US service members in Japan.

While US President Barack Obama and Japanese Prime Minister Shinzo Abe affirmed their security alliance during Abe's visit to Washington more than a week ago, Abe's new cabinet is seeking Washington's nod to modify its pacifist constitution and give it the right to exercise collective-defense.