The last leg of her trip is to the Laotian capital of Vientiane, where she will engage in summit talks with leaders from the 10-member Association of Southeast Asian Nations.

Her trip has been arranged amid tensions with China and Russia over the planned deployment of an advanced US anti-missile system to South Korea. She is likely to use her trip to seek understanding from Beijing and Moscow over the deployment plan, observers said.

Since Seoul and Washington announced the plan to station a Terminal High-Altitude Area Defense system on the Korean Peninsula in July, Beijing, along with Moscow, has vehemently opposed it, claiming it would destabilize the region and undermine its security interests.

Seoul has stressed that the deployment decision is an "inevitable, self-defense" measure to counter Pyongyang's growing military threats.

From Friday through Saturday, Park will attend the economic forum in Vladivostok and hold a bilateral summit with her Russian counterpart Vladimir Putin. Park is to deliver a keynote speech during the EEF to be held under the main theme of "Opening up the Russian Far East."

From Sunday to Monday, Park will attend the G20 summit, whose main theme is "Towards an Innovative, Invigorated, Interconnected and Inclusive World Economy."

At the G-20 summit, Park, along with world leaders, will discuss "inclusive and innovative" ways to stimulate economic growth and joint efforts to address volatility in the global financial market and shore up global trade, Cheong Wa Dae said.

On the sidelines of the G-20 forum, Park may hold a bilateral summit with Chinese leader Xi Jinping. Seoul's Vice Foreign Minister Lim Sung-nam flew to Beijing on Wednesday to apparently arrange a summit between the two leaders.

Should it be held, the summit would likely focus on addressing friction between Seoul and Beijing over the THAAD deployment, observers said.

From Wednesday to Thursday, Park will attend the South Korea-ASEAN summit, the ASEAN-plus-three summit, which involves South Korea, China and Japan, and the East Asia Summit, all of which will take place in the Laotian capital.

Following these summits, Park will begin her official visit to Laos, which was arranged on the invitation of Laotian President Bounnhang Vorachith.

On Friday, the leaders of South Korea and Laos will hold a summit to discuss trade, investment, development and other areas of mutual concern, the presidential office said.

US President Barack Obama will also pay a visit to Hangzhou and Vientiane to join the multilateral summits in the cities, raising the prospect of his one-on-one meeting with Park.

Should the leaders of the two allies meet, they would likely send a strong warning against Pyongyang's continued saber-rattling moves, including its recent submarine-launched ballistic missile test, analysts said.

On the margins of the G-20 and ASEAN-related summits, Park could also hold bilateral talks with her Japanese counterpart Shinzo Abe.

If their talks should take place, the two sides might reaffirm their cooperation against North Korean provocations and assess their progress on the implementation of last year's bilateral deal to settle the issue of Japan's wartime sexual enslavement of Korean women, observers said.

Park is also likely to encounter UN Secretary-General Ban Ki-moon, who will attend the G-20 summit in Hangzhou, observers said.

Ban is seen as a potential presidential contender in South Korea's election slated for December next year.

Park is to return home on Friday next week. (Yonhap)