WASHINGTON â€"  A top White House adviser said Sunday the Obama administration would strike a "balance" between upholding human rights and upholding its diplomatic relationship with China while considering what to do about escaped Chinese activist Chen Guangcheng. 

Counterterrorism adviser John Brennan's remarks on "Fox News Sunday" marked the first official comments by the administration on what appears to be a secretive and sensitive diplomatic standoff. 

The administration already is facing political pressure on the matter, with Mitt Romney releasing a statement Sunday calling on the administration to "take every measure" to protect Chen and his family. 

Brennan did not say whether the activist is hiding in the U.S. Embassy in Beijing as has been reported. But he made clear the United States is "very closely" involved. 

Chen, who has exposed forced abortions and sterilizations in villages as a result of China's one-child policy, escaped house arrest a week ago in Shandong province in eastern China. Chinese-based activists say the blind dissident was driven away by supporters and then handed over to others who brought him to Beijing. 

Brennan was pressed on "Fox News Sunday" on whether the administration might hand over the activist in order to preserve its ties with China. Brennan said they would strike a balance. 

"In all instances, the president tries to balance our commitment to human rights ... but also that we continue to carry out our relationship with key countries overseas," he said. "China-U.S. relations is very important, so we are going to make sure that we do this the appropriate way and that the appropriate balance is struck." 

He added: "The president will do whatever he thinks is in the best interest of the United States as well as the individuals involved." 

Chen's escape comes at a politically sensitive time for the U.S. This week, Secretary of State Hillary Clinton and Treasury Secretary Timothy Geithner head to Beijing for long-planned strategic and economic talks. Assistant Secretary of State Kurt Campbell began a hurried mission to Beijing on Sunday to smooth the way for the annual talks involving Clinton and Geithner. 

Meanwhile, the situation surfaced on the 2012 campaign trail, as the presumptive Republican presidential nominee issued a statement effectively warning the administration not to let harm come to Chen or his family. 

"My concern at this moment is for the safety of Chen Guangcheng and his family. My hope is that U.S. officials will take every measure to ensure that Chen and his family members are protected from further persecution," Romney said. "This event points to the broader issue of human rights in China. Any serious U.S. policy toward China must confront the facts of the Chinese government's denial of political liberties, its one-child policy, and other violations of human rights. Our country must play a strong role in urging reform in China and supporting those fighting for the freedoms we enjoy." 

While Chen escaped a week ago from Dongshigu village and made it 370 miles northwest to Beijing, his wife and 6-year-old daughter were left behind. The whereabouts of several other relatives, including Chen's mother and brother, are unknown. 

Seven lawyers have volunteered to defend Chen's nephew, Chen Kegui, who allegedly confronted and stabbed local officials who stormed his house in the middle of the night on Thursday in apparent retribution for the activist's escape. 

The Associated Press contributed to this report.