Kramer, the US assistant secretary of state for democracy, human rights and labour, said he had asked Chinese officials to investigate the reports.
He also restated the US position for China to improve its human rights record ahead of the Beijing Olympics in August.
In response to the talks, China called for the US not to interfere in its internal affairs on human rights issues.
"There should be no double standard or any interference in each other's internal affairs by making use of the human rights issue," said Qin Gang, a Chinese foreign ministry spokesman.
Kramer praised China for its openness in handling the devastating May 12 earthquake that killed more than 67,000 people.
"The government responded in a very remarkable way. This has brought China closer together and it has also brought other countries closer to China," he said.
Several Chinese activists complained that they were being harassed by police ahead of the talks.
Mo Shaoping, a lawyer who often represents activists, said police warned him not to accept a lunch invitation from US officials although he said he went anyway, the Associated Press reported.
Another activist reported being followed by police.
"I myself now have a police car parked in front of the door. Wherever I go, a police car follows," Aids activist Wan Yanhai wrote in an article published on Monday on the popular Chinese-language site Boxun.com. The US-based site is reportedly banned in China.
"If it were not for the police visit, I would not have known there was going to be a Sino-US human rights dialogue," he added.
The two nations began a human rights dialogue in the wake of the 1989 Tiananmen Square protests in which Chinese troops violently crushed pro-democracy demonstrations, resulting in the deaths of hundreds, if not thousands, of people.
However, the dialogue was suspended after the US tabled a resolution at the UN condemning China's human rights record.