Concern over economic competition from China has been a theme of the U.S. race for the White House, with President Barack Obama defending his record and Republican challenger Mitt Romney promising tougher tactics.

Here is a comparison of Romney and Obama's positions on China and other trade issues:

U.S.-CHINA

The U.S. trade deficit with China has swollen through both Democratic and Republican administrations from $6 million in 1985 to a record $295 billion in 2011, reflecting both China's rise as a global manufacturer and the large role that consumer demand plays in fueling the U.S. economy.

The U.S. Trade Representative's office has filed 15 cases against China at the World Trade Organization since March 2004. Eight were brought by the Obama administration and seven by the Republican administration of George W. Bush.

Obama this year created a new trade enforcement unit to bring together resources from across the executive branch to make sure China and other countries follow the rules.

Romney says Obama has not been aggressive enough in challenging unfair Chinese trade practices and he would bring a "fresh and fearless approach" to that trade relationship, using both the threat of U.S. sanctions and coordinated action with allies to force China to abide by global trade rules.

He says the United States does not have to accept "a huge and seemingly perpetual trade deficit with China" and must demand U.S. companies have the same freedom to sell in China that Chinese firms have to sell in the United States.

CHINA TIRES CASE

In September 2009, Obama used an anti-import surge provision of China's entry agreement to the WTO to slap duties on tire imports from China for three years.

The case stood out because Bush rejected several similar petitions on the grounds that restricting imports would not be in the United States' economic interest and that other foreign suppliers would fill the gap.

Romney, in his book "No Apology," criticized Obama's decision to slap tariffs on Chinese tires as "protectionism" that would stifle U.S. productivity and as a political payoff to unions for supporting his 2008 campaign.

Beijing challenged Obama's tire tariffs at WTO and lost. The tariffs expire in September.

CHINA CURRENCY

One of the most highly charged issues in the U.S.-China economic relationship is China's exchange rate.

Many lawmakers and manufacturers accuse Beijing of deliberately undervaluing its yuan currency against the dollar to give its companies an unfair price advantage.

Obama has disappointed many of his supporters by declining to formally label China a currency manipulator, even though during the 2008 campaign he criticized Bush for not taking that step.

Instead, like Bush, Obama has used diplomatic pressure to encourage Beijing to raise the value of its currency against the dollar and can point to some success.

The Peterson Institute for International Economics estimated in May that China's currency was undervalued by 7.7 percent against the dollar, compared to its July 2008 estimate that the yuan was undervalued by 31.5 percent against the dollar.

Peterson scholars say their April estimate was based on a drop in the International Monetary Fund's forecast of China's current account surplus and note the yuan has fallen in value against the dollar about 1 percent since then.

Romney has promised to declare China a currency manipulator on his first day in office.

He also would allow the Commerce Department to impose countervailing duties on imports from China if Beijing continues to undervalue its currency, an option the Obama administration considered but rejected.

TRADE PROMOTION AUTHORITY

Trade Promotion Authority, also known as "fast track" trade legislation, allows the White House to negotiate trade agreements it can submit to Congress for straight up-or-down votes within 90 days and with no amendments,

The Bush administration used it to negotiate trade agreements with 16 countries in Latin America, the Middle East and the Asia-Pacific region before the fast track authority expired in June 2007.

Obama has not sought to renew the legislation, which is generally considered essential to encouraging other countries to make their best offers in trade talks with the United States.

Administration officials have said they will seek trade promotion authority "at the appropriate time," which some analysts believe could be 2013.

Romney says he would seek immediate renewal of trade promotion authority to negotiate new trade deals.

BILATERAL AND REGIONAL TRADE AGREEMENTS

Obama won ratification of Bush administration trade deals with South Korea, Colombia and Panama after negotiating changes to make them more acceptable to Democrats.

He also has pushed forward with negotiations on the Trans-Pacific Partnership, another Bush initiative, and has overseen expansion of the regional free trade talks to 11 countries: the United States, Australia, New Zealand, Vietnam, Malaysia, Singapore, Chile, Peru, Brunei and soon Canada and Mexico.

Obama has been exploring free trade talks with the 27-nation European Union, with a decision on whether to launch negotiations expected by the end of the year.

Romney says he would use trade promotion authority to complete the Trans-Pacific Partnership pact, to pursue a bilateral deal with the EU and explore free trade pacts with other countries such as Brazil and India.

Romney has proposed creation of the "Reagan Economic Zone," a super-sized free-trade agreement among countries willing to open their markets further than required by the WTO.

WORLD TRADE TALKS

Many developing countries hoped Obama would breathe new life into moribund world trade talks launched in late 2001.

Instead, the new U.S. team followed the same line as the Bush administration in demanding that major developing countries such as China, India and Brazil agree to deeper tariff cuts and other market openings as part of a final deal.

While trade scholars continue to tout ideas for reviving and concluding the Doha round, there has been little discussion of the WTO talks in the presidential campaign.

However, the United States and roughly 20 other WTO members have been exploring the idea of negotiating an international services trade agreement, an initiative likely to continue whoever is the White House in 2013.

The Obama administration also has pushing WTO members for an expansion of the 1996 Information Technology Agreement, which eliminated tariffs on computers and other technology goods. (Reporting by Doug Palmer; Editing by Jackie Frank)