South Korean President Park Geun-hye left for The Hague on Sunday for a gathering of global leaders aimed at preventing nuclear terrorism, as well as for a rare meeting with Japanese Prime Minister Shinzo Abe on its sidelines.

The meeting with Abe, though it's a three-way get-together also involving U.S. President Barack Obama, will mark the first formal talks between Park and Abe since they took office more than a year ago, and it signals a thaw in badly frayed ties between Seoul and Tokyo.

Park has avoided a meeting with Abe as Japan kept angering South Korea with a series of nationalistic steps and remarks denounced as attempts to glorify its militaristic past and whitewash its atrocities, including Tokyo's sexual enslavement of Korean women during its 1910-45 colonial rule.

The meeting was set up after Abe promised earlier this month to honor Japan's two previous apologies for the colonial rule -- known as the "Kono Statement" and the "Murayama Statement" -- and Park welcomed the pledge.

Improvement in relations between South Korea and Japan would resolve one of the U.S.' headaches in Asia. Washington has pressured Seoul and Tokyo to come to terms with each other as it seeks to expand security cooperation with its Asian allies in part to keep a rising China in check.

The international standoff over North Korea's nuclear program and other issues related to the communist nation are expected to top the agenda for Park's talks with Obama and Abe. It is expected to be difficult for the meeting to take up the issue of history rows between Seoul and Tokyo.

The three-way talks are one of the meetings Park plans to hold on the sidelines of the biennial Nuclear Security Summit, whose third session is set for Monday and Tuesday.

Park is also scheduled to hold one-on-one talks with Chinese President Xi Jinping upon arrival in The Hague early on Monday (Korean time), their fourth meeting since she took office a year ago and the first this year.

The two leaders are expected to exchange opinions mainly on pending issues on the Korean Peninsula, including North Korea's nuclear program, and ways to further relations between their countries.

The nuclear conference brings together heads of state and other top officials from 53 countries for discussions on how to make the world safer without nuclear weapons. The inaugural summit was held in Washington in 2010 and the second summit in Seoul in 2012.

As head of the chair country of the previous summit, Park is scheduled to make a speech in the opening session, where she plans to stress the importance of the international community working together to prevent nuclear terrorism and present a way forward, officials said.

Park is one of the three leaders to make a speech in the opening session. The other two are Dutch Prime Minister Mark Rutte and United Nations Secretary General Ban Ki-moon. During the conference, Park plans to announce what South Korea has done to improve nuclear security and discuss with other leaders the future of the summit.

While in The Hague, Park plans to hold a one-on-one meeting with Rutte to discuss ways to expand economic cooperation between the two countries and exchange views on major regional and global issues. She is also scheduled to attend a lunch hosted by Dutch King Willem-Alexander.

From the Dutch city, Park will head to Germany for a state visit.

The four-day trip will be watched closely because Park could unveil a new vision for unification with North Korea during a speech at a university in the former East German economic center of Dresden.

Dresden is also symbolic in German unification as it is where former German Chancellor Helmut Kohl made a landmark pro-unification speech in 1989. Park will be the first South Korean president to visit a city in former East Germany.

South Korean leaders have sometimes used trips to Germany to announce new proposals or policies on North Korea. In 2000, former President Kim Dae-jung issued the "Berlin Declaration" calling for the end of the Cold War on the Korean Peninsula and lasting peace between the two sides.

Three months after the declaration, Kim held the South's first-ever summit with North Korea.

Park will begin the German trip with a visit to Berlin, where she plans to hold a meeting with six former officials of East and West Germany to seek their advice on unification. They include former West German Foreign Minister Hans-Dietrich Genscher, former West German Interior Minister Wolfgang Schauble, who is Germany's current finance minister, and former East German Prime Minister Lothar de Maiziere.

In recent months, Park has made strong pitches for unification, saying it would be a "bonanza" for the two Koreas as well as a blessing for neighboring countries. She also ordered the creation of a presidential committee to prepare for unification.

In Berlin, she will also hold separate talks with German President Joachim Gauck and Chancellor Angela Merkel. Cooperation on unification is expected to among the key topics for both meetings, along with expanding economic cooperation between the two countries.

Park and Merkel have forged a personal bond since they first met in 2000 when Park visited Germany as leader of the then opposition party. Merkel was also the first foreign head of state to call Park to congratulate her on winning the 2012 presidential election.

The two last met in September on the sidelines of a Group of 20 summit in Russia.

On her way home, Park will make a brief stop in Frankfurt to hold a meeting with South Korean residents, including former miners and nurses sent to Germany in the 1960s to earn hard currency for South Korea's economic development when Park's father, former President Park Chung-hee, was in office. (Yonhap)