President Obama shakes hands with South Korean President Park Geun-hye during a news conference at the East Room of the White House on May 7. (Alex Wong/GETTY IMAGES)

President Obama and his South Korean counterpart, Park Geun-hye, presented a unified front Tuesday against North Korea’s aggressive recent actions, calling on the isolated nation to give up its nuclear program as promised in return for international aid and acceptance.

Speaking at a joint news conference after morning White House meetings with Park, Obama said North Korean leader Kim Jong Un’s belligerent attempts to divide the United States and South Korea have not succeeded. He also reasserted Washington’s commitment to defend South Korea and U.S. allies in the region from North Korean aggression.

“Today is further evidence that North Korea has failed again,” Obama said. “The days when North Korea could create a crisis and elicit concessions, those days are over.”

The visit is Park’s first overseas trip as president and comes as the United States and South Korea mark the 60th anniversary of their mutual defense treaty. Park, whose father was assassinated while he held the presidency, became South Korea’s first female president in February.

Obama had a strong working relationship with Park’s predecessor, Lee Myung-bak, with whom he reached a free-trade agreement after difficult negotiations.

Obama and Park had spoken by phone amid the North Korean threats, but this visit marked their first face-to-face meeting. On Wednesday, Park will address a joint meeting of Congress, an opportunity that Obama said was reserved for “our closest friends.”

Obama and Park said the two discussed a range of common interests, including the global economy, energy policy, the Syrian civil war and U.S. plans in Afghanistan. But, as expected, North Korea emerged as the most pressing mutual concern, and the leaders made clear that Kim would not secure new assistance or support through threats.

“North Korea will not be able to survive if it only clings to its development of nuclear weapons at the expense of its people’s happiness,” Park said. She offered aid in cooperation with other nations if the North Korean leadership lived up to its international agreements.

In an interview after meeting with Obama, Park said she had not abandoned her campaign promise to build trust with North Korea. Although South Korea remains willing to work with the United States and the international community to help with the North’s development, she said, she envisions a “new kind of Korean Peninsula” where “we would never tolerate North Korean nuclear weapons, provocations would carry consequences, and threats would not pay.”

Trust, she said, “is about keeping the window open at all times” for dialogue. “Of course, I would meet with him if the need arose,” she said of Kim, the young North Korean leader. “But what use would it be at this exact moment?”

Park deflected a question about South Korean interest in having its own nuclear deterrent, saying there was “no way that we can live with North Korean nuclear weapons hanging over our head” and praising U.S.-South Korean security cooperation.

In the interview, Park spoke at length about a regional organization she has proposed to increase communication and comity among the nations of Northeast Asia. She said such an organization, which she described as finding “synergy” with the administration’s rebalancing of U.S. policy toward the Asia-Pacific region, could be helpful in persuading China to take a more robust stand in reining in North Korea.

“We can’t expect China to do everything . . . but there is room for more,” she said. “North Korea is very heavily dependent on ­China. . . . They could perhaps strengthen their persuasion.”

But Park made clear that the proposed organization could be equally important in addressing what she called “historical” differences among countries of the region, specifically South Korea’s strained ties with Japan over atrocities committed during its colonial rule of Korea from 1910 to the end of World War II in 1945.

Those unhealed wounds were reopened this year when Japanese Prime Minister Shinzo Abe defended visits of senior defense officials and lawmakers to a shrine that Seoul considers a symbol of Japan’s wartime aggression. The shrine honors Japanese war dead, including those convicted as war criminals by an Allied tribunal.

Although Japan and South Korea share the same political and economic values, Park said, “the Japanese have been opening past wounds and have been letting them fester. . . . It arrests our ability to build on momentum” in areas of cooperation.

Park described the coexistence of deepening economic interdependence with historical geopolitical tensions as the “Asia paradox” and said the United States could play a significant role in helping to resolve such problems in the region.

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