President Trump's top economic adviser said Friday that the economy would eclipse 4 percent economic growth in 2018 with the tax bill in place, upping an already sunny economic forecast.

"With the tax plan, we’re going to easily see 4 percent growth next year," National Economic Council director Gary Cohn said in an interview on Fox Business.

Cohn noted that gross domestic product growth has already come in higher than 3 percent in the past two quarters, adjusted for inflation. Without the negative effects of the hurricanes, the economy would be running at near 4 percent already, he argued: "We’re at 4 percent basically now."

Four percent growth would improve on even the brightest projections for the GOP tax plan.

Federal Reserve officials expect that growth will come in around 2.1 percent for 2018.

Analyses of the Trump-backed tax overhaul suggest that it would add at most a few tenths of a percentage point to annual GDP growth. For example, the Tax Foundation, an outside think tank with a model more favorable to the tax cut, found that the House version of the bill would increase growth by around three-tenths of a percentage point a year. That would boost growth to near 2.5 percent, well short of 4 percent.