Senate leaders had hoped to hold a final vote Thursday night, but timing remained uncertain as lawmakers engaged in last-minute jockeying. The legislation also faces challenges reaching a final deal with the House.

Senate Majority Leader

Chuck Schumer

(D., N.Y.), who has led the charge for the Innovation and Competition Act, said it would help the U.S. halt a gradual decline as the world’s leader in scientific research and innovation “and lay the foundation, instead, for another American century.”

“That’s why this is a moment in history that future generations could well look back on as a turning point for American leadership in the 21st century,” he said.

Senate GOP leader

Mitch McConnell

(R., Ky.) said that “there’s broad bipartisan agreement that America needs to upgrade our competitiveness with China,” even as he urged Democrats to allow more amendments to the bill before the Senate approved it.

The bill aims to overhaul U.S. government support for science by significantly expanding the government’s role in technological research, including through the National Science Foundation. While final details were subject to change, it would authorize about $190 billion in spending to strengthen U.S. advanced technologies to better compete globally, according to a recent Congressional Budget Office analysis, although not all of that money would represent new spending.

The bill also has become a vehicle for a number of other tech-related initiatives. One would authorize about $52 billion for encouraging more semiconductor production in the U.S.

Another provision would ban downloads of the Chinese-owned social media app TikTok on all government phones. Previous bans included military and Homeland Security devices. The U.S. says TikTok data could be shared with China’s authoritarian government. TikTok has said it would never do so.

As originally envisioned, the bill would have provided $100 billion over five years for research at NSF into artificial intelligence and machine learning, robotics, high-performance computing and other advanced technologies.

An additional $10 billion would have been authorized for the Commerce Department to designate at least 10 regional technology hubs for research, development and manufacturing of key technologies.

But some lawmakers—skeptical about the bill’s focus on NSF—succeeded in shifting part of the money to the Energy Department, which oversees 17 national laboratories that date to World War II and explore a range of scientific topics.

Lawmakers supporting the change argued that giving so much new responsibility to the NSF could undermine the national laboratories’ research. They also contended that the Energy Department has a stronger record on safeguarding sensitive research.

The tug of war resulted in lawmakers paring by about two-thirds the funds that would go to the National Science Foundation’s planned new technology division, by one estimate. Some of those funds would go to the Energy Department.

Much of the NSF money also would simply continue prior-year funding, so that the new money available for research would be sharply reduced. The CBO estimated the long-term spending impact of the bill at only about $55 billion.

The lengthy debate reflects the government’s struggles to reorganize itself around the need to accelerate development of artificial intelligence and other advanced technologies, which many experts believe could become vital to new military weapons and tactics.

A panel created by Congress and led by former Google Chief Executive

Eric Schmidt

recently recommended creation of a new National Technology Foundation and a doubling of nondefense funding for AI research and development to reach $32 billion a year by 2026.

The Schumer-led bill would add a new NSF technology directorate on technology research instead.

Even if the Senate bill eventually is approved, lawmakers still must contend with the somewhat different vision that has been developed by the House Science, Space and Technology Committee. Its bill aims to establish a new directorate in the NSF that would emphasize finding solutions to a range of challenges, from global competitiveness to climate change to social and economic inequality.

Write to John D. McKinnon at john.mckinnon@wsj.com and Lindsay Wise at lindsay.wise@wsj.com