TROY, N.Y. -- President Barack Obama yesterday called for more student loans and greater investments in basic research, particularly at two-year colleges, to bolster the economy.

Speaking at Hudson Valley Community College in Troy, the president said he hoped to increase the ranks of two-year college graduates by 5 million over the next decade. He also said the United States must reclaim its position as having the highest proportion of college graduates in the world.

Mr. Obama said he wants to divert $80 billion in federal subsidies to banks that give out student loans to provide more Pell Grants. He described as a "national tragedy" the high number of students who don't finish college because of financial constraints.

"We ... know that in the coming years, jobs requiring at least an associate degree are projected to grow twice as fast as jobs requiring no college experience," he told the crowd of 300 people. "We will not fill those jobs or keep those jobs on our shores without graduating more students, including millions more students from community colleges."

Mr. Obama pledged to spend millions of dollars on basic scientific research, saying it had led to the creation of global positioning systems, the Internet and other innovations. It also can help revive upstate New York's moribund economy, he said.

"There are those who suggest that nothing government can do will make a difference; that what we've seen in places like Troy is inevitable; that somehow, the parts of our country that helped us lead in the last century don't have what it takes to help us lead in this one," the president said.

"I am here today to tell you that this is just flat-out wrong," Mr. Obama said. "What we have here is a community filled with talented people, entrepreneurial small businesses and world-class learning institutions. The ingredients are here for growth and success and a better future."

The president's appearance in an Albany suburb was somewhat awkward for New York Gov. David A. Paterson, given reports that Mr. Obama has requested that he not run for election next year. Mr. Paterson greeted Mr. Obama at the Albany International Airport and was in the motorcade to Troy, though the pair didn't ride in the same vehicle, according to Paterson spokesman Morgan Hook.

In Troy, Mr. Paterson received only tepid applause from the audience upon entering the cement-block college building where Mr. Obama spoke. A few moments later, state Attorney General Andrew Cuomo, whom many Democrats want to run for governor next year, entered and gave Mr. Paterson a hug before sitting three seats away.

Later yesterday, Mr. Obama's made the first visit of a sitting president to CBS's "The Late Show with David Letterman." He had been on Mr. Letterman's late-night program five times before, though -- most recently as a presidential candidate in September 2008.

The White House said it was a good way for the president to reach yet another audience as Mr. Obama wraps up a blitz of TV appearances, trying mainly to build support for his health care plan. As president, Mr. Obama also went on NBC's "Tonight" show when hosted by Jay Leno.

During the 40-minute taping, Mr. Obama offered his most irreverent answer yet to the question of whether some of the vitriolic reaction to his health care plan is driven at least partly by racism.

"First of all, I think it's important to realize that I was actually black before the election," Mr. Obama said to huge laughs from Mr. Letterman and the audience.

During the show, which aired last night, Mr. Letterman covered various topics with Mr. Obama, many of them serious.

Regarding the war in Afghanistan, Mr. Obama said he knows some people want him to bring troops home, and others are calling for him to increase U.S. force levels to combat the insurgency. The top U.S. commander there is warning the war could be lost without more troops.

Mr. Obama said he won't make a decision on sending in more troops, though, until he completes a comprehensive review of the war effort and settles on his next strategy. "I'm going to be asking some very hard questions," he said.

After the Letterman taping, the president returned to his midtown Manhattan hotel and quietly emerged a while later in gym clothes and a baseball cap. His destination: the church across the street for some basketball with his aides.

Today starts Mr. Obama's main mission in New York: Participation in the United Nations General Assembly.