BEIJING - Over the course of more than five hours of discussions in Beijing on Wednesday, Vice President Joe Biden and China's leader Xi Jinping held steadfast to their respective country's position regarding rising tensions in the East China Sea.

Biden said he was "very direct" when he told President Xi the U.S. does not recognize China's contentious Air Defense Identification Zone (ADIZ). He indicated the White House expects China to take steps to ease the concerns of its neighbors to avoid undue escalation. For his part, President Xi defended China's right to police the skies over the disputed islands known as Diaoyu in China and Senkaku in Japan. He said he would "take in" what Biden had to say but gave no guarantee China would consider recalibrating its position.

Aides said they did not expect Biden to leave Beijing with a concrete resolution but the outcome - a near diplomatic stalemate - almost certainly falls short of what Japan and even the U.S. might have envisioned. It also places the ball squarely in China's court.

"It's up to China," said a senior administration official traveling with Biden who spoke on the condition of anonymity.

That the two met for such an extended period of time may be due to their long-standing personal relationship. Biden has spent more time with Xi than any other leading U.S. politician, a fact that means, as one aide put it, the two men "can be very direct about difficult issues."

On Thursday, his last day in Beijing, Biden told a group of American executives doing business in China that, "China's recent and sudden announcement of the establishment of a new air defense identification zone has, to state the obvious, caused significant apprehension in the region." Whether or not Biden's visit did anything to diffuse that apprehension remains to be seen.

"We are looking to China to take steps as we move forward to lower tensions, to avoid enforcement actions that could lead to crisis," said the official traveling with Biden, "and to establish channels of communication with Japan, but also with their other neighbors to avoid the risk of mistake, miscalculation, accident or escalation."

The islands are at the center of a decades-long power struggle between China, Japan, a U.S. ally, with Taiwan and South Korea invested on the perimeter. Before traveling to China, Biden met with Japan's Prime Minister Shinzo Abe and promised to raise concerns with Chinese leaders with "great specificity."

But when he arrived in Beijing, Biden was met with an editorial in the state-run newspaper China Daily, accusing Washington of unfairly siding with Japan. It essentially predicted the outcome that came to pass by saying Biden would hit a dead end if he simply repeated, "his government's previous erroneous and one-sided remarks."

More progress was perhaps made when the two men discussed deepening concern over North Korea's nuclear program. According to a senior administration official, they talked at length about the example Iran sets, whether the same could be applicable to North Korea and "the need for pressure in order to sharpen the choice for North Korea and our common quest to have them denuclearize."

Biden will address the same issues and more when he meets next with South Korea's president Park Geun-hye in Seoul.