President Trump’s science adviser told lawmakers on Wednesday that the Trump administration intended to drastically overhaul the country’s approach to scientific research, including by shifting research funding away from universities toward individual researchers and private companies.

At a House hearing, Michael Kratsios echoed points he laid out in a report released Tuesday, titled “Science: A New Golden Age.” He said the administration would prioritize artificial intelligence, robotics and nuclear energy while reducing the government’s focus on what he called “life sciences.”

“Our ability to make transformational breakthroughs here in the United States has slowed,” Mr. Kratsios told lawmakers in the hearing on Wednesday. “Maybe we should be testing other ways to make breakthroughs than what we’ve been doing for so many years.”

Democrats countered that the Trump administration had harmed scientific research by firing staff members at federal science agencies, seeking deep cuts to research programs, canceling or freezing grants, punishing universities that Mr. Trump is unhappy with, and pushing some of the best researchers in the United States to relocate to other countries.

“Let me propose an alternative title: ‘Unleashing the Golden Age of Science in the People’s Republic of China,’” Representative Zoe Lofgren of California, the top Democrat on the House science committee, told Mr. Kratsios at the start of the hearing. “This administration has been systematically destroying the U.S. science enterprise.”

The White House billed Tuesday’s report as “the first comprehensive rethinking of the U.S. science and technology enterprise in over 80 years,” since one written by Vannevar Bush, the organizer of the Manhattan Project, which produced the world’s first atomic bomb. Dr. Bush’s 1945 report set the stage for the current system, in which the government funds basic research, universities conduct it, and private companies commercialize it.