New U.S. President Barack Obama's long-anticipated decision on Monday to lift restrictions on stem-cell funding imposed by former President George W. Bush demonstrates just how far the United States has come in rejoining the world community it used to lead. The decision, which fulfilled a campaign promise, clears the way for U.S. scientists and companies to apply for federal funding to pay for research into whether manipulating human embryonic stem cells could produce treatments or cures for many diseases. "We will lift the ban on federal funding for promising embryonic stem cell research," Obama said to applause at a White House gathering, according to the Reuters international news service. "We will also vigorously support scientists who pursue this research. And we will aim for America to lead the world in the discoveries it one day may yield." The decision reverses controversial Bush administration policies that sharply limited U.S. participation in stem-cell research already underway worldwide. "When it comes to stem cell research, rather than furthering discovery, our government has forced what I believe is a false choice between sound science and moral values," Obama said at the gathering. "As a person of faith, I believe we are called to care for each other and work to ease human suffering. I believe we have been given the capacity and will to pursue this research -- and the humanity and conscience to do so responsibly." Bush restricted federal funding to a small group of existing cells to prevent the destruction of human embryos, which and other religious conservatives consider murder. But many scientists had accused Bush of sacrificing research and subverting scientific findings for political considerations, Reuters said, not only on stem cells but on climate change policy, energy and reproductive and end of life issues. Shares of companies specializing in stem cell research rose sharply after the announcement, with Geron Corp gaining as much as much as 35 percent and StemCells Inc up 73 percent at one point. Republican Sen. Sam Brownback of Kansas issued a statement of opposition to Obama's decision. "If an embryo is a life, and I believe strongly that it is life, then no government has the right to sanction their destruction for research purposes," the statement said, according to Reuters. Stem cell experts agree that stem cells offer the potential of a new science of regenerative medicine, which could lead to a way to replace brain cells destroyed by Alzheimer's disease, reverse genetic defects such as cystic fibrosis and regrow severed spinal cords.