CHICAGO, Sept. 13 (Xinhua) -- Imposing tariff is "a very detrimental policy" and destroying the trade system, Roy Wehrle, a reputed economist and economic consultant to former U.S. President John Kennedy, said in a recent interview with Xinhua.

Talking of the ongoing trade disputes the United States has started with other countries, the 86-year-old scholar, who is also professor of economics emeritus at University of Illinois (UI), said the U.S. policy is a very short-sighted and narrow approach of nationalism.

"It (tariff) breaks up the nexus, the lattice work of all the trade relations around the world," he said.

The professor said the present trade system was built by the United States itself, Europe and China with "sweat" and "toil" over the last 50 years, but "now President (Donald) Trump comes along with a firebrand and says, let's burn this down."

Employing tariff as its main weapon, the United States has started trade conflicts with China and is in trade rows with the European Union on autos and agricultural imports.

Wehrle compared the act of imposing tariff to a little boy taking scissors and cutting all the connections. "I can tell you that it's the wrong direction ... and that won't work."

Stressing that the world trade is participated by many different countries, the U.S. scholar said, "we have to cooperate, we're all connected to that."

Most of the changes that took place in the United States are based on technology, Wehrle said, adding that it "is irresistible" that production moves to where it could get cheaper labor.

While admitting the U.S. administration has certain points in it, Wehrle said frankly, "to do it this way, that is no good," and the United States should be responsible for it.

Wehrle said when U.S. people see the consequences of non-cooperation, they will embrace cooperation. "We won't get everything that we want, but together we will make things work," he said.