The Beijing government had been conspicuously quiet about its intentions regarding the April 12-13 summit. Many speculated that China would dispatch a lower-level delegation to show its displeasure with Washington over a $6.4 billion arms sale to Taiwan and President Obama's recent meeting with the Dalai Lama, the exiled Tibetan spiritual leader.  But China's decision to attend, announced by the Foreign Ministry, could help alleviate at least some tensions. That, in turn, could help the Obama administration win China's support for more sanctions on Iran, which Beijing has long resisted.  The decision also would appear to put pressure on the U.S. Treasury Department not to declare China a currency manipulator in a report due April 15.  For Hu to visit, Chinese officials would probably have wanted assurances that he would not be embarrassed by the report on the heels of his visit, China experts said.  Kenneth Lieberthal, a senior fellow at the Brookings Institution, called the decision on the nuclear summit "a very welcome move." Skipping the 40-nation gathering in Washington, he said, would have meant that China was "substituting a bilateral concern for what should have been a multilateral decision." With Thursday's announcement, Beijing is demonstrating it can separate the two, he added.  Official media here seemed to be making much the same point, with the state-run New China News Agency saying that the government's "summit diplomacy is conducive to displaying an image of a responsible big country."  Bill Burton, the White House deputy press secretary, said the administration is pleased that China will attend the event.  "There also will be times where we disagree. I think this proves the point that despite those disagreements, we can work together on issues like nuclear proliferation," Burton told reporters aboard Air Force One for the president's trip to Maine. "I think that China understands that it's in their best interests that there isn't a nuclear arms race in the Middle East, and that's obviously something that we're going to be working on."  It is uncertain whether Hu will have any one-on-one session with Obama on the sidelines of the summit. But his brief visit could presage an official trip in the summer, which would reciprocate Obama's visit to China in November.  The Obama administration came into office hoping to forge a closer working relationship with China across a broad range of international issues, including dealing with nuclear programs in Iran and North Korea, helping forge an international agreement to combat climate change and finding ways to bolster the global economy after the financial meltdown.  But the attempts to make China a partner on global issues soon collided with some perennial bilateral sticking points that have long defined the relationship between the two powers, including the U.S. weapons sale to Taiwan, which China considers a renegade province, and Obama's meeting with the Dalai Lama in February.  U.S. officials have cited some progress on the issue of Iran. This week, the U.S. ambassador to the United Nations, Susan E. Rice, said that China has for the first time agreed to begin "serious negotiations" on the issue of sanctions.  On Thursday, Burton described that shift as a "very important step."  "The president feels that we've been able to . . . unite the global community in a way that it hasn't been united before in putting pressure on Iran and halting their drive towards nuclear weapons," he said.  Staff writer Scott Wilson, traveling with President Obama, contributed to this report.
BEIJING -- China announced Thursday that President Hu Jintao will attend a nuclear security summit this month in Washington, in what analysts described as a sign that the government is trying to put relations with the United States back on track after months of tension.