President Donald Trump told former economic adviser Gary Cohn that strong jobs numbers were proof his tariffs were working, according to Bob Woodward's new book, "Fear: Trump in the White House."

The tariffs were not yet implemented.

Additionally, most economists agree that Trump's tariffs will cause a net loss of US jobs.

Both Cohn and the White House have pushed back on Woodward's reporting.

In early 2018, Gary Cohn came into the Oval Office to show President Donald Trump the monthly jobs report. It showed another strong month for the US labor market.

"I have the most perfect job numbers you're ever going to see," Cohn told the president, according to veteran journalist Bob Woodward's new book, "Fear: Trump in the White House."

Trump was pleased with the numbers and used them as confirmation that a new policy initiative was working.

"It's all because of my tariffs," Trump said. "They're working."

But there was an issue with that logic: Trump's tariffs were not yet in place.

While Woodward is vague about the exact timing of the discussion, Cohn announced his resignation from the White House on March 6 and left for good shortly after. The first wave of Trump's tariffs, on steel and aluminum, did not take effect until March 23.

Even then, the tariffs had exemptions for major metals sources, like Canada, the European Union, and Mexico. Trump's trade war did not really heat up until June, when Trump allowed the exemptions for the allies to expire and officially announced tariffs on billions of dollars worth of Chinese goods.

Cohn pushed back on Trump's assumptions about the tariffs, as well. Cohn, a former Goldman Sachs executive, argued that tariffs would damage the economy and hurt American workers.

According to most economic research, Trump tariffs will actually cause a net job loss. In the months since Trump's tariffs went into full effect, US small businesses have started announcing tariff-related layoffs, and job growth slowed in industries hit by the tariffs.

The exchange over tariffs is another example from Woodward's book of Cohn trying to explain economics to Trump. According to "Fear," Cohn was taken aback by Trump's lack of understanding about the federal deficit. The economic adviser also resorted to taking documents off Trump's desk to prevent the president from pulling out of major US trade deals, the book said.

Cohn released a statement on Tuesday that pushed back on Woodward's reporting but did not deny individual allegations made in "Fear."

"This book does not accurately portray my experience at the White House," Cohn told the news website Axios in a statement. "I am proud of my service in the Trump Administration, and I continue to support the President and his economic agenda."

The White House has also dismissed the book, calling Woodward's reporting "nothing more than fabricated stories."