U.S. Treasury Secretary Janet Yellen on Friday rebranded the Biden administration's economic agenda as "modern supply-side economics," using a Reagan-era phrase favored by Republicans to assert that Democrats' spending plans will boost the U.S. economy's productive capacity.

Yellen said in a speech to the World Economic Forum that rather than tax cuts and deregulation, her modernized version seeks to increase labor supply and improve infrastructure, education and research to boost potential U.S. growth and ease inflationary pressures.

"Our new approach is far more promising than the old supply— side economics, which I see as having been a failed strategy for increasing growth," Yellen said. "Significant tax cuts on capital have not achieved their promised gains. And deregulation has a similarly poor track record in general and with respect to environmental policies — especially so with respect to curbing CO2 emissions."