President Park Geun-hye will go to Washington next month for yet another meeting with U.S. President Barack Obama amid fears that Japan is getting more attention.

Diplomatic sources on Monday said Korean and U.S. government officials are fine-tuning the agenda. The two presidents plan to discuss responses to North Korea's increasing nuclear threat and ways to strengthen the bilateral alliance.

Other possible agenda items are the controversial deployment of the U.S. Terminal High Altitude Area Defense system in Korea, and Seoul's participation in the 12-nation Trans-Pacific Partnership, which is central to Obama's push for an expanded American presence in Asia.

A government official said Park and Obama are likely to discuss whether to maintain "strategic patience" with North Korea and how to deal with a provocation by Pyongyang.

But the focus of the visit will be on sending a strong message of unity rather than discussing individual issues. Following Japanese Prime Minister Shinzo Abe's high-profile trip to Washington last month, there have been concerns here that Seoul is being diplomatically sidelined.

The government official said, "The task is to find a new role for the Seoul-Washington alliance within the complicated strategic composition of Northeast Asia."

Icy relations between Seoul and Tokyo will also be on the agenda of discussions. Seoul is hoping that Washington will offer reassurances that it has no intention to let Japan off the hook over atrocities it com mitted against Asian neighbors during World War II.

Park's trip is part of a round of invitations to Asian leaders. Chinese President Xi Jinping plans to go to the U.S. in September.

U.S. Secretary of State John Kerry plans to visit Seoul later this month to fine-tune the agenda, the Korean Embassy in Washington said.

