Viewers in China ate breakfast on Tuesday morning as they watched U.S. presidential candidates Barack Obama and Mitt Romney face off on foreign policy issues in a live 90-minute debate.

The highly-anticipated final debate of the 2012 U.S. presidential election aired late on Monday in the United States.

President Barack Obama and Republican challenger Mitt Romney vowed to get tough on China's trade policies but they mostly used the Asian giant as a foil to air competing domestic economic programs.

Both men focused on the economic aspects of the complex U.S.-China relationship, touching only briefly on the security challenges that fast-rising China poses to a U.S.-led alliance system in Asia.

Obama said that China was both an adversary, but also a potential partner in the international community, while Romney repeated a pledge he first made earlier this year to press China to stop its "currency manipulation" practices.

Bob Fonow, co-chair of the American Chamber of Commerce's ICT forum, who was watching the show said that candidates were strongly divided on engagement with China.

"I think Romney had a certain hostility to Russia and China and other places that we've had as enemies in the past. And I don't think we need any more enemies. America needs friends. And I think that Obama builds friendships, and he does it very well," he said.

Obama repeated his criticism that Romney had invested in firms that sent jobs to China, adding that Romney's budget would not address U.S. needs in education and research. While Romney said government deficits and military cuts under Obama had made the United States appear weak in Chinese eyes.

The Republican candidate also said that the U.S. could be a partner with China, and didn't need to be an adversary.

Ada Shen, a sustainability and social responsibility consultant native to California said she believed the candidates were treating China policy seriously.

"I guess I'm just glad to see that both candidates from their respective sides sort of addressed points that were not too China bashing, which I think would be kind of unfair. It's a really important relationship to get right, it's probably the single most important bilateral relationship for the United States, and for my part, I'm happy to see more sophistication," she said.

Romney shrugged off concerns his approach would trigger a trade war, saying there was already a trade war, that had led to a U.S. trade deficit.

Qiu Huafei, deputy dean of the school of political science and international relations at Tongji University, said it was common for presidential candidates to talk tough on China, then act more moderately once they got into office.

"Some people they don't like China, and now you know for these two candidates, they need, you know, the support from different levels of the people. So that's American domestic politics. They utilise this kind of situation in U.S. domestic politics to sell their presidential campaign. That is normal, but you know, after the presidential election, I think everything will be normal, both Republicans and Democrats they hope, you know, to improve relations with China," he commented.

Rather than strengthening the military, as Romney suggested, Obama said instead he thought investment in education and research, and taking care of domestic issues was the best way to stay ahead of China.

Despite their strong criticisms of Beijing, the candidates overall agreed that they would definitely welcome China as an ally rather than an opponent.

The United States remains one of the world's largest investors in China and still owes billions of dollars in debt to its Eastern trading partner.