Liu pointed to three major areas of disagreement: whether to cancel all trade war tariffs when an agreement is reached, the exact size of Chinese purchases of USA goods, and a "balanced" agreement text.
The US hiked tariffs on $200 billion worth of Chinese goods, prompting an escalation in a trade war between the two countries.
Chinese officials have said they will take action to answer the increase.
In comments to reporters before he left Washington for Beijing on Friday, Vice Premier Liu He said he was cautiously optimistic but that a deal would require the Trump administration to agree to end the punitive tariffs it has imposed on billions of dollars' worth of Chinese goods.
They also include Section 301 of the Trade Act, which Trump used a year ago to apply 25 per cent tariffs on $50 billion worth of Chinese goods and 10 per cent tariffs on $200 billion of goods.
The president on Saturday presented what he viewed as a simple option for affected Americans to get around these tariffs. Because it means that trade tariffs will go up, fewer goods will circulate around the world, we won't be able to circulate our own French goods as easily around the world, and jobs will be destroyed.
Last July, Trump began gradually imposing tariffs on Chinese imports.
Trump has repeatedly suggested that China will pay the cost of the increased tariffs.
Because it usually takes about three weeks for container ships to travel from Chinese ports to destinations in America, negotiators still could reach an agreement before shipments arrive.
The increasing tensions worry investors around the world.
"NO ONE WINS A TRADE WAR", trade analyst Chad Bown of the Peterson Institute for International Economics said on Twitter.
President Trump has given China one month to finalize a deal or face duties on all of its exports to the United States. China believes that tariffs were the genesis of the trade dispute, and that if both sides wanted to reach an agreement, then all tariffs must be eliminated, Liu said. He has also accused the Chinese government of backing away from earlier promises it made during the past months of negotiating.
"Some commentators have said Beijing will now call for boycotts of United States goods and place non-tariff barriers on U.S. goods".
Trump's views on trade helped forge his path to victory in states such as Pennsylvania, Michigan, Wisconsin and OH, where he linked the loss of manufacturing jobs to the North America Free Trade Agreement and other trade deals.
Under the latest U.S. action, U.S. Customs and Border Protection set a 25 percent tax on more than 5,700 kinds of products leaving China after 04:01 UTC on Friday.
Davie Stephens, ASA president and a soy grower from Kentucky, urged the US government to hear them and believe what soy farmers are saying about "the real-life consequences to our farms and families as this trade war drags on". Those cargoes will be charged the original 10% rate. "Would be wise for them to act now, but love collecting BIG TARIFFS!" he posted.
Investors worry that a worsening trade war could further damage a slowing worldwide economy. China has vowed retaliation but has not released specifics.
"There is no greater threat to world growth", French finance minister Bruno Le Maire said on Friday. If more goods are hit with tariffs, the price of those goods will inevitably rise beyond what companies can absorb without raising prices. They say the tariffs will lead to financial difficulties for American businesses, which will be forced to raise prices. The move rasied tariffs from 10% to 25% on a range of consumer products, including cell phone, computers and toys.
Mats Harborn is president of the European Union Chamber of Commerce in China.
At a recent rally in Macomb County, Michigan, for Bernie Sanders, the Vermont senator making his second run for president as a Democrat, some voters complained that Trump hasn't delivered on promises to upend US trading relationships. It can use its enormous population and other export markets as alternatives to U.S. demand to cushion the impact of the new levies. George Grow was the editor. Susan Shand adapted it for VOA Learning English.