President Park Geun-hye returned to Seoul on Sunday from her four-day trip to the U.S. with a set of diplomatic achievements such as obtaining Washington’s stronger commitment to North Korea’s denuclearization and its support for her initiatives for unification and regional peace.

Her trip also helped ease the growing impression that Seoul was tilting toward Beijing, analysts noted. During his summit with Park last Friday, President Barack Obama expressed support for Seoul to pursue deeper ties with Beijing.

Yet, there is a major task left for Park to fulfil to maintain strong ties with its security ally -- mending relations with Tokyo to strengthen the trilateral security partnership that the U.S. has been keenly fostering despite its allies’ historical animosities.

“Obama’s support for the Seoul-Beijing relations means that the U.S. sort of recognized the role of South Korea as a pivotal middle power nation, and that Seoul secured more space for it to strategically maneuver in the regional diplomatic arena,” said Nam Chang-hee, diplomacy professor at Inha University.

“However, Seoul should also read what Washington meant. Obama supported Seoul’s relations with Beijing on the premise that Seoul would try to do what it can to enhance its ties with Tokyo and the trilateral partnership involving the U.S.”

The upcoming trilateral summit among the leaders of South Korea, Japan and China is expected to be a crucial juncture for Park to improve relations with Japanese Prime Minister Shinzo Abe whose nationalist policy agenda has aggravated taut diplomatic tensions.

Both Park and Abe have expressed their willingness to hold a bilateral summit on the sidelines of the trilateral summit, which is expected to be held in Seoul in late October or early November. The two sides have not yet held a summit amid territorial and historical spats.

Another achievement from last week’s summit between Park and Obama is that the two sides agreed to strengthen their cooperation on the issue of the unification of the Korean Peninsula, analysts noted.

In a joint statement, which was seen as unusual due to its focus wholly on North Korean issues, the allies said that they would intensify “high-level strategic consultations” to create a favorable environment for peaceful unification.

Seoul officials said that the high-level consultations mean a vice minister-level or minister-level communication mechanism focusing on unification issues.

Also notable is that the U.S. offered greater support for Park’s “Northeast Asia Peace and Cooperation Initiative.” Washington appointed its Special Representative for North Korea Policy Sung Kim as an envoy dedicated to supporting the NAPCI.

Park has been pushing for NAPCI to build multilateral trust to address the “Asia Paradox,” in which regional political and security cooperation is weak, despite deepening socioeconomic interdependence. NAPCI is one of the three major external policy initiatives including the Peninsular Trust-Building and Eurasia Initiatives.

During her trip to the U.S., Seoul made yet another request that the U.S. help transfer some key technologies to build indigenous fighter jets. However, the U.S. rejected the notion, as was widely expected.

But the allies agreed to build a consultative body to promote technological cooperation in Seoul’s fighter jet development program and wider defense industry areas -- an agreement that observers said helped save face for South Korean defense officials.

By Cho Chung-un, Song Sang-ho (christory@heralddcorp.com) (sshluck@heraldcorp.com)