Prime Minister Shinzo Abe said Thursday that he wasn't informed of a Chinese navy frigate's use of fire-control radar targeting a Maritime Self-Defense Force destroyer in the East China Sea on Jan. 30 until Tuesday, admitting officials were tardy in alerting him.

Abe told a Diet committee that Defense Minister Itsunori Onodera informed him about the Jan. 30 incident on Tuesday, although he was alerted immediately after a similar radar target-lock incident occurred on Jan. 19 involving another Chinese frigate and an MSDF helicopter.

In explaining the delayed report, which could raise questions about the effectiveness of civilian control of the Self-Defense Forces, Abe said officials had a hard time trying to confirm the Jan. 19 target-lock of the chopper and "became more careful" in examining the Jan. 30 incident.

He added he will seek prompter reports of such incidents even if information is unconfirmed.

While deploring the Chinese-instigated incidents, Abe said, "It is important we not close the window for dialogue."

He called on China to reaffirm the importance of the "strategic relationship of mutual benefit," a concept Abe put forward during his 2006-2007 prime ministership in a bid to improve bilateral ties.