Trump says trade talks with China were "very productive"

U.S. President Donald Trump said on Sunday that trade talks held a day earlier with China had been "very productive".

Writing on Twitter, Trump also said Chinese President Xi Jinping has been "very helpful" before Trump's meeting with North Korean leader Kim Jong Un scheduled to be held in Vietnam on Wednesday and Thursday.

"President Xi of China has been very helpful in his support of my meeting with Kim Jong Un. The last thing China wants are large scale nuclear weapons right next door," Trump said in a series of morning tweets.