Rep. Paul Ryan, the Republican vice presidential candidate, speaks at Youngstown State University in Ohio on Saturday. (Mary Altaffer/AP)

Seeking to build on the momentum that the Republican White House ticket has picked up in recent weeks, GOP vice-presidential nominee Paul Ryan on Saturday made an appeal to voters in a Democratic area of this manufacturing state, arguing that President Obama’s China policies have cost the country jobs.

In an address to several hundred supporters in a hall at Youngstown State University, the Wisconsin congressman seized on Friday’s news that the Obama administration will delay until after the election the release of a biannual Treasury Department report on whether China is manipulating its currency. The report had been due Oct. 15.

“The administration had their eighth chance to label China a currency manipulator,” Ryan said at the outset of his town hall meeting here. “It’s due in two days. They said they’re going to push this deadline off until after the election. That’s eight opportunities they’ve had to say, ‘You know what? Play fair with us. Trade with us fairly.’ ”

The Treasury announcement follows something of a trend: The administration delayed the release of its October 2011 and 2010 reports, as well.

Ryan’s visit Saturday morning took him to the heart of the Democratic stronghold of Mahoning County, which Obama won in 2008, with 62 percent of the vote to Republican nominee John McCain’s 36 percent. His currency-manipulation remark comes as both parties have been trading barbs over which side would be tougher on China, a battle that frequently plays out in the waning weeks of campaigns.

Ryan and his running mate, GOP presidential nominee Mitt Romney, have pledged to label China a currency manipulator on “Day One” in office. On Saturday, Ryan renewed the ticket’s pledge to “do something about it” and argued that Obama has also failed to press China enough on intellectual property rights.

”We’ve lost hundreds of thousands of jobs, according to one study, because of just this problem,” Ryan said. “Two million jobs we’ve lost, according to the International Trade Commission, because of one country — China — taking our intellectual property rights.”

The 2011 U.S. International Trade Commission report states, however, not that 2 million jobs had been lost to China but rather that the tightening of intellectual property rights could lead to the creation of an additional 2 million American jobs.

The White House has defended its decision not to label China a currency manipulator, arguing that it has urged Beijing officials through diplomatic channels to allow the value of the yuan to rise and that further pressure could lead to a damaging trade war.

Responding to Ryan’s remarks, Obama spokesman Danny Kanner said that Romney’s own tax plan would cost the country jobs and that his record belies his running mate’s tough rhetoric on China.

“When President Obama stood up to China on behalf of American tire workers, Romney called it ‘decidedly bad for the nation,’ ” Kanner said, referring to the administration’s imposing tariffs on tires imported from China. “In the private sector, he led investments in companies that shipped American jobs to China, and in a Chinese company known for the cheating he condemns today.”