China Vice-President Xi Jinping in US visit
China's leader-in-waiting, Xi Jinping, has defended his country's human rights record, during a visit to Washington.
At a State Department lunch, the Chinese vice-president admitted that there was "room for improvement" on human rights.
Separately, Mr Xi and US President Barack Obama discussed trade and currency issues, as well as China's stance on Syria, officials said.
Mr Obama said a strong relationship between the two nations was "vital".
Mr Xi, meanwhile, said he hoped his visit would deepen mutual understanding and friendship between the two powers.
The 58-year-old is expected to succeed China's President Hu Jintao, who must retire as head of the Communist Party later this year and from the presidency in 2013.
The US and China have been at odds over trade, currency and human rights. Last month, China's vetoing of a UN Security Council resolution on Syria also angered US officials.
Mr Xi, who is in the US all week, said he had had a "candid exchange" regarding human rights with his US counterpart, Joe Biden, and US Secretary of State Hillary Clinton.
"I stressed that China has made tremendous and well-recognised achievements in the field of human rights over the past 30-plus years, since reform and opening up," he said.
"Of course, there is always room for improvement when it comes to human rights," he added.
His comments were similar to those made by President Hu during a trip to Washington a year ago.
But his visit comes amid concerns over a clampdown by Beijing on protests in Tibet, and outside the White House, human rights activists staged protests as Mr Xi arrived.
Some waved Tibetan flags or held signs proclaiming, "Xi Jinping: Tibet will be free."
In the Oval Office, Mr Obama was warm but firm, the BBC's Kim Ghattas in Washington says.
Washington also put pressure on Beijing over what it sees as unfair trade practices, as well as the value of its currency.
Mr Obama said he "welcomed China's peaceful rise", but added: "We want to work with China to make sure that everybody is working by the same rules of the road when it comes to the world economic system."
"That includes ensuring that there is a balanced trading flow not only between the United States and China but around the world."
Mr Xi hailed further economic co-operation with the US, saying that any issues should be resolved through dialogue, "not protectionism".
Meanwhile, Mr Obama privately told Mr Xi he was disappointed with China's veto of the UN Syria effort, according to unnamed US officials.
Later, the Chinese vice-president met Defence Secretary Leon Panetta at the Pentagon and was received with a full honour guard.
Mr Xi and Mr Panetta made short remarks at the beginning of the meeting but did not take reporters' questions.
Mr Xi is making the trip as the guest of US Vice-President Joe Biden, who made a high-profile visit to China late last year.
On Wednesday, he is due to travel to Iowa to meet his hosts during his first visit to the US in 1985 when he was a county official.
Those who had hosted him in the small farming community in Muscatine, where he toured to learn about crop and livestock practices, said they were surprised he had fitted a visit there into his US trip.
"I'm flabbergasted that he would take time out of his busy schedule and come back to Muscatine,'' said Eleanor Dvorchak, whose family hosted him for two nights.
Mr Xi will then fly to Los Angeles, California, to meet business leaders and reportedly attend an LA Lakers basketball game on Friday.
After the US trip, Mr Xi is also scheduled to visit Ireland and Turkey.