The National Administration of Surveying, Mapping and Geoinformation and the military will jointly conduct a detailed survey of the country's islands, including the Diaoyu Islands, Li Zhigang, director of the National Geomatics Center of China told the Beijing News on Monday.

The surveying and mapping process is a fundamental step to safeguard the country's maritime interests, Li said on the sidelines of a press conference in Beijing on Monday.

The survey will be divided into two phases: islands within 100 kilometers of the shorelines, and islands beyond 100 km of the shorelines, such as the Diaoyu Islands, which is about 300 km away from the shorelines, according to Li.

He added that China has already finished the first phase of the mapping process of 6,400 islands, covering about 1.9 million square kilometers, which may be released to the public in June.

Due to the illegal occupation by some countries of islands under Chinese sovereignty, the work is facing some difficulties, said Zhang Huifeng, director of the surveying development and research center of the National Administration of Surveying, Mapping and Geoinformation.

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