WASHINGTON - Former US presidential candidate Jon Huntsman on Thursday criticized his ex-rival Mitt Romney's policy toward China, saying it's "wrongheaded" to threaten a trade war with Beijing.

"It's not unusual for candidates to be saying certain things about China," the former US ambassador to China and former Utah governor said on MSNBC's Andrea Mitchell Reports. "I've seen a lot of candidates who later became president, who use a lot of rhetoric. It's much easier to talk about China in terms of the fear factor than the opportunity factor."

Huntsman made the remarks when asked to comment on the former Massachusetts governor's op-ed in Thursday's Wall Street Journal blasting the Obama administration's China policy.

Romney has repeatedly threatened to designate China a currency manipulator and take counteraction on day one of his presidency if he were elected, a move strongly opposed by the US business community.

"When it comes to China, I think it's wrongheaded when you talk about slapping a tariff on day one," Huntsman said. "That pushes aside the reality, the complexity of the relationship."

Huntsman dropped out of the Republican presidential nomination race last month and announced endorsement for Romney.

While disagreed with Romney on China policy, Huntsman defended his endorsement, saying Romney is "best-placed to do what needs to be done in terms of economic development and the creation of jobs. "