File Photo: A bike fan visits the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

SAN FRANCISCO, May 23 (Xinhua) -- The booming outdoor economy of the United States will take a hard hit from the tariffs that the U.S. government has imposed and proposed to levy in the coming months, an industry expert said on Thursday.

"The Trump administration has proposed multiple rounds of target lists for tariffs and China has responded in kind," said Rich Harper, manager of international trade at Outdoor Industry Association, at a webinar for industry companies.

Earlier this month, the United States increased additional tariffs on 200 billion U.S. dollars' worth of Chinese imports from 10 percent to 25 percent, and has threatened to raise tariffs on more Chinese imports.

The outdoor recreation industry was initially hit by the earlier 10 percent tariff list, which included products such as backpacks, camp chairs, camp stoves, bikes and kayaks. The subsequent tariff increase has affected outdoor products such as apparel (including performance outerwear), footwear, tents, sleeping bags, skis, snowboards and sporting goods.

"In other words, everything else," said Harper. Some items excluded from prior lists are back, such as snow sports helmets and rifle scopes, he added.

The increased tariffs will further raise costs for outdoor manufacturers, suppliers and retailers and cut already thin profit margins, the association said in a recent letter to U.S. President Donald Trump.

The ongoing trade dispute and higher tariffs will devastate one of the nation's strongest industries, which is a major contributor to the growing 887- billion-dollar outdoor recreation economy and makes up over 2 percent of the U.S. gross domestic product, said the association.

Higher tariffs mean less money for new American jobs and could also force small and medium-sized businesses to close, it said.

The public hearings to help determine the list of products will be held on June 17. The association has warned its members to be prepared for tariffs to go into effect as early as mid-July.

"We are strongly encouraging you to come and participate in the public hearing ... and actively engage with the Congress and the administration," Harper told the webinar. "Together we can push back against these tariffs."