Obama:Agreement to secure nukes by 2014

WASHINGTON (AP) - President Barack Obama says all 49 leaders attending a nuclear security summit have endorsed his goal of securing nuclear materials around the world within four years.

Obama acknowledged Tuesday that the goal won't be easy.

He says, however, that the group agreed that the threat of nuclear terrorism is among the largest challenges to global security. He says the urgency of the threat brought leaders together around his four-year goal.

Closing the session in Washington, Obama said leaders made several specific promises to change the way nuclear materials are handled.

Obama said Tuesday he is confident China will join other nations in pressing for tough new sanctions on Iran for continuing to defy the international community in seeking nuclear weapons.

"Words have to mean something. There have to be some consequences," Obama told reporters at a news conference at the conclusion of the two-day gathering.

He was asked about China's reluctance in the past to join other major nations in backing tough sanctions.

Chinese President Hu Jintao on Tuesday gave a speech to the group calling for "effective" measures to safeguard nuclear weapons and materials but stopped short of mentioning Iran's program.

Hu and Obama met for 90 minutes on Monday after which U.S. officials said the two agreed to tell their aides to work on a tough new sanctions program. However, a Chinese spokesman did not mention sanctions in his description of the meeting.

China imports oil from Iran and in the past had been reluctant to endanger that supply line.

"The Chinese are obviously concerned about what harm this might have on the economy generally," Obama said. "Iran is an oil-producing state. ... A lot of countries around the world have trade relationships with Iran and we're mindful of that."

Obama said Hu had assured him that China would participate in drafting sessions at the United Nations on a new strong sanctions regime.

"I think that we have a strong number of countries on the Security Council who believe this is the right thing to do," Obama said. "But I think these negotiations can be difficult, and I am going to push as hard as I can to make sure that we get strong sanctions that have consequences for Iran as it is making calculations about its nuclear program and that those are done in a timely basis."

China is one of five permanent members of the Security Council with veto powers, along with the U.S., Russia, Britain and France.

Obama said that the new sanctions would make it easier to isolate Iran, as the global community had done for North Korea as it continued to develop nuclear weapons.

Obama said Pyongyang had chosen a path of "severe isolation," which has hurt the North Korean people. Obama said he hoped sanctions would add pressure on North Korea's leaders to return to the six-party talks.

"Sanctions," Obama acknowledged, "are not a magic wand."

But Obama said he believes the U.S. approach would make it more likely for North Korea to alter its behavior rather than allowing the communist nation to operate its nuclear program without consequences.

On an area of major disagreement with China, Obama acknowledged that he did not win a concession from Hu that China would move to let its currency rise with market forces.

China sees the matter as "a sovereign issue," Obama said. However, he emphasized, "It is actually in China's interest to achieve this rebalancing."

China currently pegs its currency, the yuan, to the U.S. dollar. American manufacturers claim this severely holds down the price of Chinese products in other markets, making their own goods less competitive.