Japan and the United States plan to wait until early October to finish drawing up an interim report on the planned revision to bilateral defense cooperation guidelines, as they need to spend more time on its wording, a government source said in Tokyo.

The Japanese government is apparently concerned that the report, depending on how it is worded, will take center stage in the Diet's extraordinary session this fall, while the United States is trying to tread carefully not to provoke China, the source said Friday.

The report is now expected to be compiled when senior Japanese and American officials at the director general level gather in Washington in early October to discuss the new guidelines, which are expected to be finalized by the end of the year, according to the source.

The two countries had planned to arrange a meeting in late September of their foreign and defense ministers under the so-called two-plus-two consultative framework, and to release the report, as the 69th session of the U.N. General Assembly will be held around the same time.

The focus of the first revision in 17 years is on how much of an expanded role the Self-Defense Forces will take under the bilateral alliance, especially in logistical support.

Tokyo's decision in July to enable the use of the right to collective self-defense, or going to the aid of allies under armed attack even when Japan is not directly threatened, will also be reflected in the updated guidelines.