"China has always advocated that all parties resolve economic and trade differences through equal dialogue and consultation," foreign ministry spokeswoman Mao Ning said.

"At the same time, relevant negotiations and agreements should not target or harm the interests of third parties," she said.

The deal announced on Wednesday is the first full pact Trump has sealed with an Asian nation, and analysts say it may give a glimpse of the template Washington will use with other countries still hoping for accords.

It comes less than a week before Trump's self-imposed July 9 deadline for steeper tariffs on US trade partners to take effect if agreements are not reached.

Shares in clothing companies and sports equipment manufacturers -- which have a large footprint in Vietnam -- rose on the news, but later declined sharply after Trump released details including the continued tariffs, which were higher than expected.

Trump's trade adviser Peter Navarro has called Vietnam a "colony of China", saying that one-third of Vietnamese products are in fact relabelled Chinese goods.

Beijing's commerce ministry said on Thursday it had "always firmly opposed" US tariffs.

"China's position is consistent," He Yongqian, spokeswoman for China's ministry of commerce, told a briefing.

"We are happy to see all parties resolve economic and trade differences with the United States through equal consultations, but we firmly oppose any party reaching a deal at the expense of China's interests," she said.