The European Union has decided to negotiate with Japan toward concluding a security and defense partnership agreement, with the bloc seeking to elevate bilateral ties to a higher level, an EU document showed Monday amid China's maritime assertiveness.

The two sides will explore increasing cooperation across wide areas including maritime security, intelligence sharing and coping with hybrid attacks — a new form of warfare that combines military and nonmilitary tactics such as distributing fake information to achieve strategic objectives.

The move comes after Japan and the EU vowed to "develop further (their) security partnership" in a joint statement following their summit meeting last July, amid concerns about China's growing clout in the East and South China seas.

Calling Japan a "key partner in the Indo-Pacific" region, the document said the two sides are "longstanding partners in the field of peace, security and defense and have significantly developed their relationship in these areas over the past few years."

The EU called for "reinforcing cooperation to the next level," the document said after the bloc's Foreign Affairs Council meeting.

Among 14 areas the EU listed as being considered as a focus for boosting ties with Japan is maritime security, including conducting exercises — in an apparent reference to joint drills in the Indo-Pacific region — alongside possible cooperation on strengthening Southeast Asian nations' maritime security capabilities.

Other areas include responding to cyberthreats, protecting critical infrastructure, and coordinating on counterterrorism, space security and defense, the document said.

At its summit meeting in June last year, the EU said in a statement that "the East and South China Seas are of strategic importance for regional and global prosperity and security," adding that the bloc is concerned about growing tensions in the Taiwan Strait.