NEW YORK -- U.S. President Joe Biden's nominee for ambassador to China, Nicholas Burns, spoke harshly of Beijing at his Senate confirmation hearing Wednesday but endorsed Washington's long-standing "One China" policy and so-called strategic ambiguity regarding Taiwan as effective.

Strategic ambiguity has for decades meant that Taipei cannot be sure whether America will come to its defense if China mounts an attack on the island -- but also that Beijing cannot be sure that it won't. This deters China from taking action in the Taiwan Strait, supporters of the policy say.

Sen. Ted Cruz, a Republican from Texas, said the Chinese Communist Party interprets strategic ambiguity as weakness and asked Burns whether the U.S. should make its commitment to the defense of Taiwan more clear.

"My own view is that we're better off, and we'll be more effective in staying with the 'One China' policy of the last four decades," the former State Department spokesperson and ambassador to NATO said. "We recognize the People's Republic of China as the sole legal government of China. And yet we have unofficial relations with Taiwan, and we have under the Taiwan Relations Act the ability, in fact, the imperative, of helping Taiwan to defend itself. Every president, Republican and Democrat, has followed that policy."

The Taiwan Relations Act of 1979 stipulates that the U.S. will make available to Taiwan defensive arms to be able to protect itself. It also says the U.S. will "consider any effort to determine the future of Taiwan by other than peaceful means, including by boycotts or embargoes, a threat to the peace and security of the Western Pacific area and of grave concern to the United States."

"Maybe the most important thing we can do is maintain the American military position in Japan, in the Republic of Korea and that First Island Chain, but also out to our Andersen Air Force Base in Guam, and to be an effective deterrent to keep the peace," Burns said.

The nominee did acknowledge that China has become more of a challenge in recent years.

"The PRC seeks to become the most powerful country economically, politically and militarily in the Indo-Pacific," Burns said, using the initials of its official name. "We have to stand with our allies and our friends to uphold a free and open Indo-Pacific, including by maintaining America's commercial and military superiority in 21st-century technologies."

Painting China as a bully, Burns rattled off a list of victims.

"Beijing has been an aggressor against India along their long Himalayan border; against Vietnam, the Philippines and others in the South China Sea; against Japan in the East China Sea. And Beijing has launched an intimidation campaign against Australia, and even more recently Lithuania," he said.

"The PRC's genocide in Xinjiang, its abuses in Tibet, its smothering of Hong Kong's autonomy and freedoms, and its bullying of Taiwan are unjust and must stop," Burns continued. "Beijing's recent actions against Taiwan are especially objectionable."

Sen. Tim Kaine, a Democrat from Virginia, noted that the U.S. once had leverage over China through annual reviews of its most-favored-nation trade status. That status was made permanent in 2000, ahead of China's entry into the World Trade Organization. "The decision was made because of a belief that if China was part of the WTO, they would conform themselves to global trade rules, and I think everyone, whatever their thought at the time, would say that China's behavior has been disappointing," Kaine said. He asked Burns whether the move was a mistake.

"The assumptions that many made about China in those years turned out not to be accurate," Burns said in his response. "And China took advantage of its presence at the WTO as a so-called developing country."

"I do think at this point in 2021, I hope there'll be bipartisan support for a very aggressive American policy to hold China to account," he said.

Asked about the recent collaboration between China and Russia, including a joint passage by their warships through Japan's maritime chokepoint of the Tsugaru Strait on Monday, Burns said: "A lot of us, maybe 10, 20 years ago ... would not have anticipated that China and Russia would begin to work together strategically, but they are."

"There are 6 or 7 million Russians living east of the Ural Mountains in that vast expanse," he said. "And there are 3 or 400 million Chinese living below them. The Russians are going to have to worry, long-term, about economic domination of Russia by China."

"The Russians ought to be worried about a Chinese nuclear weapons buildup in the western part of China, about the hypersonic missile ... and the fact that China is completely unconstrained. Of the five permanent nuclear powers of the Security Council, it's the only one that refuses to be part of any arms control regime," Burns said. "We've been part of one for 60 years, since the Test Ban Treaty of 1963. And so, obviously, that's going to be a focus for all of us, I would say, including the Russians, going forward."