WASHINGTON China has turned down a proposed fence-mending visit by the U.S. defense secretary, Robert Gates, during his trip in the region this week in what some American officials described as a snub to protest U.S. arms sales to Taiwan.
Beijing has delayed several high-level military exchanges since January, when the Obama administration notified Congress of a plan to sell Taiwan up to $6.4 billion in arms.
But the proposed visit by Gates, who leaves for Asia on Wednesday, was the highest-level postponement to date and a sign of continued friction in relations at a time when the Obama administration needs Beijing's help to rein in tensions on the Korean peninsula and to curb Iran's nuclear program.
Gates has spoken out publicly about his hopes to visit Beijing and to put military-to-military cooperation between the United States and China back on track.
He will be in Singapore starting on Thursday to attend a major security conference but Pentagon press secretary Geoff Morrell said a proposed China leg "did not come to be."
A senior U.S. defense official said the Chinese told their American counterparts that it was "not a convenient time" to host Gates but they were not explicit about the reason why.
"It certainly wouldn't be beyond the realm to speculate that this is sort of continued ... reaction to the Taiwan arms sale," the official said on condition of anonymity.
Another U.S. official called it a worrisome "rebuke" given heightened tensions in the region after the United States and South Korea concluded that North Korea was behind the sinking of a South Korean warship in March that killed 46 sailors.
Morrell played down the implications for coordinating Korea policy, saying: "There is not a lack of communication between our respective governments."
China is sending a delegation to the Singapore security conference, but Gates is not scheduled to meet with them.
"China is not sending a very high level delegation to this conference, certainly not an appropriately high level to meet with the secretary," Morrell said.
In Singapore, Gates plans to meet with his South Korean counterpart to convey "our full support for the way in which the Korean government has been handling the crisis" with the North, the senior U.S. defense official said.
"Our commitment to the defense of Korea is and remains unequivocal and that we're committed to continuing to work with Korea and our other allies and partners in the region to try to lessen the threat that North Korea poses to regional stability," the official said.
FRUSTRATED BY 'PATTERN'
The Pentagon has expressed frustration with what U.S. officials see as a Chinese "pattern" of curtailing military contacts in response to policy disputes with Washington.
"He (Gates) just doesn't believe that a relationship of this importance can take place in fits and starts. There needs to be a continuous, high-level engagement between these two powers and it can't be derailed by bumps in the road that will inevitably come up," Morrell said.
"We are very much interested in engaging and we think they need to be more interested in engaging," he added.
Daniel Blumenthal, a China desk chief at the Pentagon under former President George W. Bush, said any Chinese shunning of Gates underlined the fragility of U.S.-China security ties. "The relationship is basically one of tension, punctuated by some moments of cooperation," said Blumenthal, now a member of a U.S. congressionally mandated commission that studies the national security implications of U.S.-China trade.
Defense officials said Beijing and Washington were looking to reschedule Gates's visit for a later date.
In addition to the Gates trip, China has postponed planned visits to the United States by its chief of the General Staff, as well as by one of its top regional military commanders.
China has for years opposed U.S. defense sales to Taiwan, which Beijing regards as a renegade province to be united with the mainland, by force if necessary.
U.S. officials say that Taiwan needs updated weapons to give it more sway with Beijing.
The island has a standing request to buy 66 new Lockheed Martin Corp-built F-16C/D fighter jets, a request that Obama administration officials have said is under review.
China also suspended military-to-military exchanges in 2007 after the administration of former president Bush announced the previous planned series of U.S. arms sales to Taiwan. Beijing restored those ties, only to break them off again after the latest big U.S. arms sale plan was unveiled in late January.
Senior U.S. administration officials have urged China to maintain military-to-military contacts, partly as a hedge against misunderstandings or accidents that could lead to confrontations.
(Additional reporting by Jim Wolf; Editing by Eric Walsh)