Barack Obama has warned Donald Trump to practice caution when dealing with the One-China policy for fear that weakening ties could lead to a breakdown of relations with the Asian country. Speaking at a news conference at the White House on Friday, 16 December, the president said it was good to subject the current US policies on China and Taiwan to "fresh eyes", but one should be aware of provoking a "very significant response".

"For China, the issue of Taiwan is as important as anything on their docket," Obama said. "The idea of one China is at the heart of their conception as a nation and so if you are going to upend this understanding, you have to have thought through what ... the consequences are."

Obama urges Trump to be cautious on the One-China policy REUTERS/Carlos Barria

Trump drew criticism from China after taking a call from Taiwanese president Tsai Ing-wen and later suggesting he would review the One-China policy and use it as a bargaining tool to improve trade deals with Beijing.

"If you're going to upend this understanding, you have to have thought through what the consequences are because the Chinese won't treat that like they treat some issues. They won't even treat it the way they treat issues around the South China Sea, where we've had a lot of tensions," the president said.

"This goes to the core of how they see themselves. And their reaction on this issue could end up being very significant. That doesn't mean that you have to adhere to everything that's been done in the past."

Under the decades-old policy, China has allowed Taiwan to maintain a certain level of autonomy as long as it would not attempt to declare independence from the mainland. "That status quo, although not completely satisfactory to any of the parties involved, has kept the peace and allowed the Taiwanese to be a pretty successful... economy and a people who have a high degree of self-determination," Obama explained.

Referring to US-China relations, the Democratic leader stressed that "there is probably no bilateral relationship that carries more significance ... And where there is also the potential — if that relationship breaks down or goes into a full conflict mode — that everybody is worse off," he added.

Watch Obama's complete take on the US-China issue in the White House video below: