US President Donald Trump's first phone call to President Xi Jinping shouldn't be over-interpreted, experts on China-US relations said, while urging that both countries strengthen cooperation on issues ranging from defusing tensions on the Korean Peninsula to increasing "reciprocity" in bilateral relations.

In their "lengthy and cordial" telephone conversation on the evening of Feb 9, Trump agreed to honor the one-China policy, a shift from his earlier saying that he might not do so unless China made big concessions on trade. Trump and Xi also agreed that the two countries should discuss and negotiate issues of mutual interest.

"Reiterating its commitment to the one-China principle is the least Washington can do to maintain its relations with Beijing," said Niu Jun, a professor of US studies at Peking University. "It should not be over-interpreted, because it marks no significant breakthrough but ‘a(chǎn) return to normal'."

On future cooperation, combating cross-border terrorism and defusing tensions on the Korean Peninsula are likely to see closer interaction between both sides, Niu said, adding that both countries share increasing concerns over the two issues, and would at the very least seek to avoid increasing their differences.

Both Washington and Beijing expressed their opposition to last weekend's test launch of a missile by the Democratic People's Republic of Korea. China's Foreign Ministry said on Monday that Beijing "has been striving for a settlement of the Korean Peninsula issue by proactively engaging in mediation and promoting peace talks", while Trump vowed to deal with DPRK "very strongly".

Simon Lester, trade policy analyst of the Washington-based Cato Institute, a think tank, agreed that the presidential phone call was a sign of a good relationship, "but there are still many hurdles to overcome," he added.

His view was echoed by Nicholas Hope, former director and China program director of the Center for International Development at Stanford University.

"Recognizing the importance of the one-China policy as a foundation stone of the relationship gives me greater optimism for a more fruitful dialogue on equally vital issues, specifically, trade and investment relations and agreements to combat climate change," Hope said.

The intense interdependence shared by the world's largest and second-largest economies means that bilateral trade and financial cooperation is also inevitable, according to Zhu Feng, director of the Institute of International Studies at Nanjing University.

With Trump's diplomatic approach showing a distinctive tendency for "negotiations", it's important that Beijing responds to and addresses Washington's concerns about the Chinese market, Zhu said.

As many of Trump's cabinet picks are proven trade hawks obsessed with reversing the US trade deficit, two-way trade remains the most vulnerable to confrontations, said Zhang Zhixin, head of American political studies at the Institute of American Studies, China Institutes of Contemporary International Relations.

Zhang said that besides traditional agendas such as nonproliferation and fighting pirates, there is plenty of room for both countries to cooperate on infrastructure and energy. "But that depends on the political importance the Trump administration attaches to them," he added.

In addition to developing relations with the US, Shi Yinhong, a director of the Center of US Studies at Renmin University of China, said, "China should also accord priority to neighborhood diplomacy and improve its ties with major regional powers, especially those in alliance with the US."

David M. Lampton, a professor and director of China Studies at Johns Hopkins University, said he had told The Wall Street Journal before the inauguration that there is a long tradition of politicians running on anti-China bumper stickers, and that Trump would probably have to "negotiate back from some of these positions".

"Welcome as his reaffirmation of the long-standing one-China policy of the US is, the US administration's move has at least two downsides," the former president of the National Committee on US-China Relations wrote in an email.

"To start, what is the policy process that leads to such volatility in foundational policy statements? It is hard to have confidence in any decisions when the process is so sloppy and subject to change," Lampton said. "I do worry about credibility. Will the administration be taken seriously when it counts in a crisis, whether with China or any other country?"

Lampton said that the US's China policy should be "broadened and modified" in the direction of achieving more "reciprocity".

"I think building a Sino-American dialogue on the themes of achieving a stable balance in Asia geopolitically, cooperation between China and America to jump-start global growth, and bilaterally achieving more reciprocity in Sino-American relations is an agenda that could stabilize bilateral relations and appeal to Americans and the Asia-Pacific region," he said.