US President Donald Trump has welcomed his Chinese counterpart Xi Jinping at a mansion in his private resort in Florida, and their first meeting has begun, a media report said.

Trade and North Korea's nuclear program were expected to be the major focus at the West Palm Beach mansion, located in Trump's private resort Mar-a-Lago, Efe news reported.

After arriving at the Palm Beach International Airport, Xi and his wife, Peng Liyuan, were greeted by US Secretary of State Rex Tillerson.

Around an hour later, Trump and First Lady Melania Trump arrived by the presidential plane Air Force One.

The activities scheduled for the leaders of the world's two largest economies, which will last about 24 hours, began on Thursday afternoon with tea and dinner receptions.

"It is a great honour to have the President of China and his incredibly talented wife, a great, great celebrity in China, a great singer. It's an honour to have you in the US," Trump said minutes before the dinner.

Trump briefly explained to the journalists who accompanied him that he and his counterpart "had a long discussion already".

"So far, I have gotten nothing. Absolutely nothing. But we have developed a friendship. I can see that. I think, long-term, we are going to have a very, very great relationship, and I look very much forward to it," Trump added, without giving further details.

The formal part of the summit will be held on Friday with a series of discussions, and will conclude with a working luncheon.

Before leaving for his private club, Trump said on Thursday in Washington that "nobody really knows" what could come out of the summit with Xi.

However, he repeated assertions that China has not been "fair" with the US regarding trade and that North Korea poses "a very big problem."

"We have not been treated fairly on trade for many, many years. No presidents have taken care of that the way they should have. And we have a big problem with North Korea. We're going to see what happens," Trump added in a brief interview with US broadcaster Fox.

Asked if his goal is to get China to put pressure on North Korea, the President said only that "we're going to see what happens," adding that he will raise his argument with Xi and thinks it is "going to do very well".

Trump told The Financial Times newspaper on Sunday that he was "totally" ready to act unilaterally against Pyongyang's threats, saying that "if China is not going to solve North Korea, we will."

The Republican President is set to warn Xi that "the clock has run out" for patience in diplomatic efforts, and that Washington now has "all options on the table," a White House official said Tuesday.

Trump will put pressure on China to "strictly implement UN resolutions and sanctions" on North Korea, since about 90 per cent of Pyongyang's foreign trade is with Beijing, according to the same source.

Tillerson on Thursday used softer language and said that the US is hopeful that China will "find ways to exercise influence on North Korea's actions to dismantle their nuclear weapons and their missile technology program."

It is expected that trade will be another major theme of the summit, where Trump will focus on the lack of trade balance between the US and China.

However, the White House has not yet clarified whether the US leader will exert any pressure on Xi to stop currency manipulation.

Both leaders will also address human rights issues in China, White House spokesperson Sean Spicer said Thursday without giving further details.

Meanwhile, the Chinese President is expected to continue pushing against the deployment of US anti-missile system THAAD in South Korea, which he considers a threat to his country.

Xi is also expected to insist on his country's sovereignty over the South China Sea dispute.

However, the US has not shown signs of willingness to give in on either issue.