Shandong, China (CNN) -- When it comes to China's military relationship with the United States, U.S. Admiral Mike Mullen is not one to mince his words.

"We don't have a relationship, it was stopped," the chairman of the U.S. Joint Chiefs of Staff says after climbing down from one of China's high-tech combat planes during a rare visit to the headquarters of the People's Liberation Army in Shandong province.

But he stresses the two countries better build one, and high level contact like this, he hopes, will create closer ties that will benefit not just the region, but the world.

During his visit, Mullen watched an aerial display by two Russian-designed SU-27 fighter jets -- considered a match for any other combat aircraft.

It was a carefully orchestrated display by China's military bosses, designed to impress.

As would be expected from a trip behind the normally closed doors of a PLA military base, everything about this trip has been scripted.

But for the international media, including CNN, this is rare access indeed, even if our every move is scrutinized.

Mullen remains largely off-limits except for one moment when I am able to throw a couple of questions. He answers fully and willingly, but within minutes he is ushered away.

Mullen says China is not a rising military power -- it has already risen. He says that military might carries great responsibilities and the need for more openness.

He hopes this trip will bring the China and the United States closer.

But he is quick to remind China that the United States has a crucial stake and key allies in the Asia-Pacific and it isn't walking away.

"The United States has enduring interests in the region. We will continue to support those enduring interests and we want to do it in a way that is supportive of this relationship as well," he says.

Mullen's Chinese counterpart, General Chen Bingde, is quick to add that China too has its interests and there are lines that can't be crossed.

"The sole purpose of our forced development is to ensure our territorial integrity, national security, and to prevent the secessionist forces from Taiwan to separate Taiwan from the country," Chen says.

Much still divides the two countries.

China is not happy about the United States participating in war games off its coast. And it still bristles at American arms sales to Taiwan, which Beijing considers a renegade province awaiting reunification.

The United States, for its part, remains concerned about potential aggression from North Korea and China's territorial disputes with Vietnam, the Philippines and Taiwan in the South China Sea.

So what of the China-U.S. military relationship? In Admiral Mike Mullen's words there may not be one just yet, but much hinges on building those ties -- and soon.