US President Donald Trump has said the US will be prepared to act alone to counter nuclear threat from North Korea "with or without China's help".
In an interview with the Financial Times, Mr Trump said: "If China is not going to solve North Korea, we will. That is all I am telling you."
Pressed on whether he thought he could succeed alone, he replied: "Totally."
Mr Trump is due to meet Chinese President Xi Jinping this week in Florida.
"China has great influence over North Korea. And China will either decide to help us with North Korea, or they won't. And if they do that will be very good for China, and if they don't it won't be good for anyone," Mr Trump told the newspaper.
Asked what incentive the United States had to offer China, Mr Trump replied: "Trade is the incentive. It is all about trade."
It is not clear whether Mr Trump's comments will move China, which has taken steps to increase economic pressure on Pyongyang but has long been unwilling to do anything that may destabilise the North and send millions of refugees across their border.
It is also unclear what the US might do on its own to deflect North Korea from the expansion of its nuclear capabilities and from the development of missiles with ever-longer ranges and the capacity to deliver atomic warheads.
Mr Trump's national security aides have completed a review of US options to try to curb North Korea's nuclear and missile programmes that includes economic and military measures but leans more towards sanctions and increased pressure on Beijing to rein in its neighbour, a US official said.
Although the option of pre-emptive military strikes on North Korea is not off the table, the review prioritises less-risky steps and "de-emphasises direct military action", the official added, saying it was not immediately known if the National Security Council recommendations had made their way to Mr Trump.
The White House declined to comment on the recommendations.
Mr Trump and Mr Xi are also expected to discuss Chinese ambitions in the South China Sea, through which about $5 trillion in ship-borne trade passes every year, when they meet on Thursday and Friday.
China claims most of the resource-rich South China Sea, while Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims on the strategic waterway.
Mr Trump's deputy national security adviser, KT McFarland, said there was a "real possibility" North Korea could be capable of hitting the US with a nuclear-armed missile by the end of Mr Trump's four-year term, the Financial Times reported.
Mr McFarland's estimate appeared more pessimistic than those of many experts.
"The typical estimates are that it will take five years or so," said Siegfried Hecker, a former director of the Los Alamos National Laboratory in the US and a leading expert on North Korea's nuclear programme.
Such estimates are hard to make both because of the scarcity of intelligence about North Korea and uncertainty about how high a success rate Pyongyang might want for such missiles.
