U.S. Secretary of State Hillary Clinton is urging North Korea's new leadership to choose what she calls the “path of peace” following the death of North Korean leader Kim Jong Il.

Clinton said late Monday that she hoped North Korea would be committed to “improving relations with its neighbors and respecting the rights of its people.”

She also expressed concern about the well-being of the North Korean people, saying the U.S. was ready to help the isolated communist nation to “usher in a new era of peace, prosperity and lasting security” in the region.

Earlier, Clinton spoke with Japanese Foreign Minister Koichiro Gemba, where she said the U.S. and Japan share a common interest in a stable and peaceful transition of power in Pyongyang. She also said both governments have been in close touch with other participants in the six-nation talks on North Korea's nuclear programs, including China, Russia and South Korea.

Meanwhile, President Barack Obama told Japan's Prime Minister Yoshihiko Noda by telephone late Monday that Washington was committed to the defense of its allies and the stability of the Korean peninsula.

Mr. Obama spoke earlier Monday with South Korean President Lee Myung-bak. A White House statement said Mr. Obama, in his talks with Mr. Lee, had reaffirmed Washington's strong commitment to “the security of our close ally, the Republic of Korea.” The statement said the leaders agreed to continue close coordination between their respective national security teams.

In Seoul, President Lee canceled all of his scheduled events, convened a National Security Council meeting and placed the South Korean military on emergency alert. South Korean media say aerial surveillance near the North Korean border has been stepped up.

The two Koreas have remained technically at war since 1953 when their three-year conflict ended only with an armistice, not a peace treaty.

China – North Korea's closest ally – offered condolences to the North Korean public, while Japanese Prime Minister Noda convened a meeting of senior advisors to formulate a response to the North Korean leader's death.

In New York, U.N. General-Secretary Ban Ki-moon offered condolences to the North Korean people and reaffirmed his long-standing commitment to peace and security on the Korean peninsula. The official gesture came as the U.N. General Assembly condemned human rights abuses in North Korea – a vote taken annually by the world body.

In London, British Foreign Secretary William Hague said Mr. Kim's death could be a turning point for North Korea. He also said Pyongyang's engagement with the international community offers the North its best hope for improving the lives of ordinary North Koreans.

French Foreign Minister Alain Juppe said France is wary about the consequences of a power transfer in the secretive communist state. He voiced hope that North Korean citizens will gain expanded freedoms.