Foreign governments are uncertain about President Donald Trump.

China, as a rising power, sees his missteps as opportunities to expand its influence.

But Trump's unpredictability is cause for concern in Beijing and elsewhere.

President Donald Trump has been a source of amusement and frustration for foreign governments, which are frequently unsure whether his public pronouncements reflect the policies he will pursue.

That mismatch is felt acutely in China, which stands alongside the US as the preeminent overall powers in Asia, according to the Asia Power Index compiled by Australia's Lowy Institute.

But Chinese leaders, unsure as they may be about Trump, see opportunities in his approach to the world stage, according to Kevin Rudd, Australia's prime minister between 2007 and 2010 and in 2013.

"Strategically, they regard the Trump administration as an enormous opportunity for China," Rudd said on Tuesday at the Asia Society in New York, during an event marking the Asia Power Index report's release.

"They see vacuums and spaces opening up around the world ... through the absence of an effective American diplomacy, as well as in key institutions," like the United Nations or even NATO.

'A retrograde step'

Former Australian Prime Minister Kevin Rudd, left, at the Munich Security Conference in Germany, February 16, 2018. REUTERS/Michaela Rehle

Rudd said he and others had urged Chinese President Xi Jinping to talk to Trump about keeping the US in the Iran nuclear deal in order to avoid imperiling a potential deal with North Korea over its nuclear program. It's not clear whether such communication ever took place, and Trump pulled the US out of the Iran deal on Tuesday.

"I would think on balance, the Chinese would see this a retrograde step, because it makes the potential enforceability of any regime which the North Koreans would agree to, to be more problematic in the execution," reinforcing the Chinese perception that US foreign policy hinges on domestic politics, Rudd said, pointing to decisions like the withdrawal from the Paris climate accord.

"As to whether see the Chinese this as a further strategic opportunity, America being in global diplomatic disarray, I think that is now taken as a strategic given in China," which sees the Trump administration "as being all over the place."

"They see that the fracturing of US traditional alliances, both in Asia and in Europe, over a whole range of different questions," Rudd added. "So the Chinese see this as an opportunity to frankly — I won't say exploit American weaknesses — but simply to move into vacuums."

Trump bumps fists with Japanese Prime Minister Shinzo Abe during a round of golf, November 2017. Kyodo/Reuters

Others have made similar points about China seizing on missteps by Trump.

Trump's at-times contentious dealings with Asian allies on issues like trade and military commitments, and his seeming disinterest in things like foreign aid, has strained relations with those countries, according to Ian Bremmer, president of geopolitical-risk-firm Eurasia Group.

"The willingness of these countries to actually coordinate with the Americans on China policy is virtually zero at this point," Bremmer told Business Insider in February.

While Beijing is not replacing the US, "certainly it is taking advantage of situations in which the United States would have a certain dominance in the past, and now, as they retreat from the world, China sort of capitalizes [on] those opportunities," Jorge Guajardo, who served as Mexico's ambassador to China between 2007 and 2013, told Business Insider in March.

'They're very uncertain about this guy'

Even as those moves appear as opportunities to China, Trump's policymaking style is cause for concern.

"Here's the qualifying point," Rudd said on Tuesday. "They find Trump strategically comforting and tactically terrifying, and why do I say that? Tactically terrifying because they actually do not know which way he will jump."

Rudd pointed specifically to Trump's broadsides against Beijing over the US's trade deficit with China.

While Chinese leaders had not previously expected US presidents to take action over the issue, Trump "has jumped up and down and begun to indicate what national measures the United States would take," Rudd said. "He has now grasped China's attention."

The US and China are currently in talks on the matter. At China's request, US Treasury Secretary Steven Mnuchin visited Beijing to meet with Chinese economic policymakers at the beginning of May, and Chinese Vice Premier Liu He is set to visit the US to continue those discussions, though a date has not been set.

While China has reportedly pushed back on some US requests, Mnuchin's visit to China is said to have yielded a mutual agreement "that a sound and stable China-US trade relationship is crucial," as well as a working mechanism to strengthen communication between the two countries on trade issues.

But the issue is not settled, and uncertainty about what Trump will do leaves Chinese leaders ill at ease.

"China prefers strategic predictably, not uncertainty," Rudd said, "and they're very uncertain about this guy."