Even so, the US dollar hit a six-month high against the safe-haven Japanese yen as currency traders put trade worries aside and focused on Labor Department data that showed producer prices rising more than expected.
Analysts expect to see the impact of the tariffs in July's figures.
In turn, the Trump administration accused China of not negotiating "seriously" on trade and released on Tuesday a list of $200 billion worth of Chinese exports that could be subject to new 10-percent tariffs. China also said both its imports and exports with the USA rose in the first half of 2018.
The June figures may have received a boost from USA and Chinese traders who rushed to fill orders for soybeans, ball bearings and other goods in both directions before threatened tariff hikes took effect.
Pressed on the possible negative impact of multiple trade disputes on the USA economy, Mnuchin said the Trump administration was keeping a watchful eye. Its trade surplus with the U.S. over the same period was $133.76bn, up from $117.51bn previous year.
The expanding trade surplus was largely because of smaller imports.
While China continues to benefit from strong global demand for its goods for now, the rising trade tensions with the United States has the potential to hurt both sides.
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Spokeswoman Lindsay Walters adds in her statement that "this is consistent with what we have been saying all along". But you never know what happens.
USA stocks closed higher on Thursday as industrials rebounded and technology names soared, while commodities recovered and the dollar held steady after concerns over an escalating US trade war with China took a breather.
David Kuo, chief executive of the Motley Fool Singapore, said "US tariffs will increase the cost of Chinese imports but they are unlikely to deter U.S. consumers entirely".
Imports grew 14.1 percent in June, customs said, missing analysts' forecast of a 20.8 percent growth, and compared with a 26 percent rise in May.
China's commerce ministry confirmed last month that Chinese exporters were front-loading shipments to the United States to get ahead of expected tariffs - a situation that could exacerbate any slowdown in shipments toward the year-end.
"There will be challenges facing foreign trade with rising instabilities and uncertainties in the global environment, " said a Chinese customs agency report.
"So we would be back to square one", Mr Kuo said, with China exporting more to the U.S. than it buys from the country.
Earlier on Thursday, President Donald Trump said the United States was in a nasty trade battle with China, but things would ultimately work out.