Unpredictable shifts in trade policies coming from the White House are keeping Volvo Cars executives guessing about how tariffs and treaties could affect operations at its first U.S plant - a $1.2 billion investment that's projected to bring thousands of jobs to South Carolina.

"I would say it's new things every day," Anders Gustafsson, head of Volvo's U.S. operations, said of President Donald Trump's evolving trade rhetoric.

"If you ask me whether I monitor it and whether Volvo Cars is monitoring the situation, well, of course, every minute," he said. "We need to have plans to handle the situation."

Trump's announcement last month that he would impose steep tariffs on imports of foreign-made steel and aluminum — and the expected trade war such a move could prompt — caused Volvo CEO Hakan Samuelsson to question whether the company's future Berkeley County plant would really need the 4,000 workers the automaker has promised to hire by 2021.

The Volvo campus is scheduled to begin building a redesigned S60 sedan this summer, with a second production line for XC90 SUVs to be introduced in three years.

The automaker plans to export about half of the 150,000 vehicles that will be produced annually by that time, all through the Port of Charleston.

"We are creating 4,000 jobs and the idea was that half of the production would be exported," Samuelsson told Bloomberg News in March. "Basically, if we cannot trade freely, of course, then you can question, can we really employ the 2,000 people extra?"

Gustafsson echoed those comments during a visit to the nearly completed South Carolina plant this month.

"Of course there will be complications, because everything is related to volume," he said. "If you don't have the volume, you don't need the people."

He adds that Volvo isn't changing its plans, but is taking a wait-and-see attitude toward trade policy impacts.

"It's a little bit too early to talk about it," Gustafsson said. "We believe in free trade. So let's see how we are going to handle it."

The initial tariffs announcement has been softened, with Trump now saying he will exempt many of the countries the U.S. currently does business with.

However, Trump more recently threatened to impose tariffs on a wide range of goods from China, the world's largest exporter and America's top trading partner. China, in turn, has said it will place tariffs on U.S.-made products.

Volvo is owned by China-based Geely Holding Group, and the automaker has a pair of manufacturing plants in that country that ship vehicles to the United States. But Gastafsson said the company has so far managed to avoid any consequences from Trump's tough talk targeting China.

"We run our business with a little bit of common sense," he said.

The tariff threats follow Trump's efforts to withdraw from the North American Free Trade Agreement, which the president has criticized as being "the worst deal ever." Talks to renegotiate the treaty between the U.S. Mexico and Canada are ongoing. Trump has called for boosting the required percentage of American-made parts in vehicles manufactured in the U.S., a move automakers say will raise prices.

More recently, Trump said the U.S. might rejoin the Trans-Pacific Partnership — an agreement among Asian allies the president denounced as "a rape of our nation" during his 2016 campaign. Trump formally withdrew the U.S. from the partnership more than a year ago.

The head-swiveling policy stances are keeping Volvo and other foreign-based firms on their toes — and wary of fallout.

"Of course, it's going to give us implications," Gustafsson said of the trade edicts coming out of Washington. "But that's really how it is to run a business."

Reach David Wren at 843-937-5550 or on Twitter at @David_Wren_