The United States does not seek an adversarial relationship with China; the two countries have a broad relationship featuring both contention and cooperation, US State Department spokesperson Heather Nauert said on Thursday.

"China is obviously an important regional and world power, we work closely with China on issues related to North Korea, on issues related to trade and many other issues as well," Nauert told a briefing at the Washington Foreign Press Center.

Asked to comment on how she would categorize the relations between the world's two largest economies, Nauert said, "It is an important relationship, it's a broad relationship, we don't seek an adversarial relationship with China."

Over the past week, Washington has ratcheted up rhetoric and action against China. The US National Defense Strategy released on Jan 19 cites China as a "strategic competitor", taking a more confrontational stance than the previous administrations.

This was followed by a harsher tone toward Beijing, including a Monday decision to impose steep tariffs on imported solar products and washing machines, a move that China called an "abuse" of trade remedies.

Nauert said that "we simply identify actions China has taken that we view as undermining rules-based order", but overall, the US' relationship with China hasn't changed.

"It's a broad relationship but similar to other countries, we have areas of disagreement, we will have conversations, we will have frank conversations, but we also have areas of cooperation," she said.

The spokesperson's remarks seemed to echo Cui Tiankai, China's ambassador to the US, who chose the word "partners" to describe current China-US ties, a term he said is closer to reality than "adversary", "rival" or even "enemy".

Cui said in an interview with the USA Today on Tuesday that in the first year of the Trump presidency, the China-US relationship has been stable and made some "important positive progress".

"Of course, we still have problems, but China-US relations never run short of problems," Cui said. "It is making progress in the process of problem solving, and we expect to do the same in the future."

Nauert also said the US supports the kinds of contacts and conversations about the Olympics between the Democratic People's Republic of Korea and the Republic of Korea, saying, "It's good to have conversations, to be able to pick up the phone and have a conversation with your neighbor, so that we support, and we look forward to having a terrific Olympics in South Korea."

She said the US position on the DPRK has not changed. Its goal is denuclearization for North Korea.

"We are willing to have talks with the North Korean regime, but the time is not right now," she said. "They know what they need to do."