China represents the biggest state threat to the UK’s economic interests and is a systemic challenge for the world order, Prime Minister Rishi Sunak told NBC on his trip to the US.
Mr Sunak said countries must take steps to protect themselves, as the US did when alarms were raised recently over Chinese spy balloons.
The incident and China’s behaviour in the South China Sea are concerning, he said.
He said the country was acting in ways that were not aligned with the values shared by the UK, US, Australia and other allies.
Mr Sunak also discussed his opinion on the origins of Covid-19 after recent reports from the FBI that it was "likely" to have come from a laboratory leak in China.
“There's clearly questions that need to be answered,” he said. “I'd certainly say that and we haven't ruled anything out at this stage.
“I think what we want to see and fully support is a proper scientific inquiry as to the origins and we would urge everyone, including China, co-operate with that investigation.”
Mr Sunak moved on to China's role in Russia's war in Ukraine, saying the country already gives crucial economic aid to Moscow.
Asked if he would support sanctions on China, Mr Sunak said: “I think with sanctions that it's always something that is best done co-ordinated with allies, because for sanctions to be effective we have to do them together.”
Current US-Chinese tension - in pictures
He said the UK would “accelerate and intensify” its support for Ukraine when asked if he will provide fighter jets to the war-torn nation, saying it is important that “they have an opportunity to have a decisive advantage on the battlefield".
Although France and Germany have suggested the war will end through negotiation, Mr Sunak said: “I think, ultimately, those decisions are for Ukraine to make.”
“Our job is to put them in the best possible position to make those decisions — we want to see Ukraine victorious.”
Mr Sunak said King Charles appointing him as Prime Minister was a very special moment in his life.
“Now I have the privilege of sitting down with him every week," he said. "Good discussions, great discussions, you know, he's trying to modernise the monarchy.”