From The Hague to the former East German city of Dresden, South Korean President Park Geun-hey sought to address mainly two hard questions that could define her presidency: how to end North Korea's nuclear program and how to unify with the communist nation.

North Korea was the dominating topic in every stop of Park's weeklong trip that first took her to The Hague for a gathering of world leaders aimed at preventing nuclear terrorism and then to the German cities of Berlin and Dresden for a state visit.

The trip came as Park seeks to carve out a legacy on North Korea during her term ending in early 2018. From the beginning of this year, she has been making strong cases for the benefits of unification, saying it would be an economic "bonanza" not only for the two Koreas, but also for neighboring countries as well. 

The highlight of the trip was Park's speech laying out a roadmap for unification. 

Park's proposals called for the South and the North to first cooperate on humanitarian issues, such as the reunions of separated families and humanitarian economic aid, before expanding economic cooperation to bigger projects as trust builds between the two sides.

"Now more than ever, South and North Korea must broaden their exchanges and cooperation," Park said in the address at the Dresden University of Technology in the former East German city of Dresden.

"What we need is not one-off or promotional events, but the kind of interaction and cooperation that enables ordinary South Koreans and North Koreans to recover a sense of common identity as they help each other out."

She said that she believes Germany overcame the after-shocks of unification fairly quickly and achieved the level of integration of today because of the sustained people-to-people interaction that took place prior to unification.

Should North Korea give up its nuclear program, Park said that the South will work aggressively to help North Korea win international development funds for economic development. Seoul is also willing to establish a Northeast Asia Development Bank to help develop the North, she said.

"North Korea must choose the path to denuclearization so we can embark without delay on the work that needs to be done for a unified Korean Peninsula," she said. "I hope North Korea abandons its nuclear aspirations and returns to the six-party talks with a sincere willingness to resolve the nuclear issue so it can look after its own people."

The standoff over North Korea's nuclear program dominated Park's discussions in The Hague.

In the opening session of the Nuclear Security Summit that brought together the leaders of 53 countries, Park appealed that ending North Korea's nuclear program should be the first step toward an ambitious vision to make the world free of nuclear weapons.

She said that Pyongyang's pursuit of atomic bombs poses grave threats to world peace because nuclear material from the communist nation could end up in the hands of terrorists. She also voiced concerns that a small accident in the North's nuclear complex could lead to a disaster worse than the 1986 Chernobyl nuclear disaster.

"As long as North Korea remains a nuclear challenge, a world without nuclear weapons will not come," Park said in the speech.

"It has been my long-held conviction that the journey toward a world without nuclear weapons should start from the Korean Peninsula."

On the sidelines of the conference, Park met one-on-one with Chinese President Xi Jinping and talked about the nuclear issue.

The two leaders reaffirmed that a nuclear North Korea is unacceptable, and agreed to cooperate closely to restart the six-party denuclearization talks.

She also held a three-way summit with U.S. President Barack Obama and Japanese Prime Minister Shinzo Abe, a rare gathering set up as part of U.S. efforts to help the two American allies mend frayed relations caused by issues related to Japan's colonial rule of Korea in the early 20th century.

The three leaders focused discussions on the nuclear standoff without talking about history and other thorny bilateral matters.

They agreed to convene a meeting of their chief nuclear envoys and other trilateral sessions to forge a united front against the North.

Her visit to Germany was mostly about unification. 

In talks with Chancellor Angela Merkel, Park said Germany is a model for Korea to follow. The two leaders also agreed to work closely together to share the lessons of German unification to help South Korea chart a course for its own unification with the North.

Merkel also said she believes it is Germany's obligation to help realize Korean unification.

In a meeting with German President Joachim Gauck, Park repeatedly said that Korean unification will surely come, and pledged to make steady preparations for it.

"I firmly believe that there will come a day when our cease-fire line will fall," she said. (Yonhap)