Jakarta, CNN Indonesia --

Chinese President Xi Jinping  raised the issue of Taiwan, in a telephone call with United States President Donald Trump on Monday (24/11).

Xi called Trump after China engaged in a weeks-long"war of words" with Japan, a key US ally, over Taiwan.

"China and the US once fought side by side against fascism and militarism, and now must work together to secure the outcome of World War II," Xi said.

"Given what is happening, it is all the more important for us to jointly safeguard the victory of World War II," Xi told Trump, AFP reported.

The heated exchange between China and Japan was sparked by a statement by Japan's new Prime Minister Sanae Takaichi, who said her country would intervene militarily in any attack on Taiwan.

Although it does not officially recognize Taiwan's claims, the US is one of Taiwan's most important partners and arms suppliers.

Following the call, Trump praised the"very strong" US-China relationship in a social media post, though he did not mention Taiwan.

China's Foreign Ministry said in the phone call that Trump told Xi that the US"understands how important the Taiwan issue is to China."

China considers Taiwan part of its territory and has repeatedly asserted that it will use force to control the island. However, Taiwan has repeatedly rejected China's claims and asserted that only the Taiwanese people can determine their future.