During Tuesday's hearing on US relations with China the committee heard concerns over China's military development, criticism over its recent test of an anti-satellite weapon and alarm over its rising defence budget.
 
Dana Rohrabacher, a Republican and long a critic of China, said the US had played a significant role in giving China the wherewithal to become a military power because of China's robust US-bound exports.
 
"We have built up a Frankenstein that now threatens us," Rohrabacher said.
 
In a similar vein another Republican representative, Ileana Ros Lehtinen, pointed to figures that China was planning a 17.8 per cent increase in its military budget for the next financial year.
 
"Who's the target?" she asked.
 
Falling short
 
Opponents of China's support for Sudan
joined the committee hearing [GALLO/GETTY]
Giving testimony to the committee, John Negroponte, the US deputy secretary of state, said China needed to be "more open about its military budget, doctrine, and intentions".
 
The motives behind China's military build-up are unclear and are of concern to both the US and China's neighbours, he said.
 
Negroponte is the chief adviser to Condoleezza Rice, the US secretary of state, on China and the rest of Asia.
 
During his testimony, he agreed with China's critics that Beijing falls short on a number of issues.
 
But, he said, the overall picture was not uniformly negative, noting that until recently it would not have been possible to imagine China supporting UN Security Council sanctions against North Korea - as it did last year after Pyongyang tested a nuclear weapon.
 
"They are capable of shifting," Negroponte said. "They are changing."
 
'Genocide Olympics'
 
Sitting behind Negroponte were a group of people wearing shirts carrying the slogan "Genocide Olympics?", a reference to Beijing's support for the Sudanese government, despite its role in the violence in Darfur.
 
Several committee members also criticised China's support for Sudan, prompting Negroponte to agree that Beijing was seen as "Khartoum's diplomatic patron and benefactor".
 
But he also said the US had had a "measure of success" in persuading China leaders of the need to respond to the human suffering in Darfur.
 
Negroponte was speaking as human rights group Amnesty International released a letter signed by 96 senators to Hu Jintao, the Chinese president, urging him to increase pressure on Sudan to halt military operations in Darfur.
 
Specifically, the letter called on Hu to reconsider his offer of an interest-free loan to Sudan to build a presidential palace in Khartoum.
 
"We believe that extending such a loan would clearly send the wrong message," it said.