President Barack Obama's multi-tasking abilities will be tested this week as he juggles war, diplomacy and finance on the world stage while dealing with the US public's top concern: the US economy.

As he prepares for three days of meetings at the United Nations followed by a two-day global financial summit in Pittsburgh, Obama seems determined not to let up on his drive to reassure his domestic audience about his handling of issues at home such as the economy and healthcare.

Before going to New York City for the UN meetings, Obama visited Troy, a community 140 miles north, to tell middle-class families he was well aware of the toll that global competition and boom-bust cycles have taken on their efforts to earn a living.

Contraction in the manufacturing sector has caused "many years of hard times" for local families, Obama said during a visit to a community college.

"Communities like this one were once the heart of America's manufacturing strength," he said. "But over the last few decades, you've borne the brunt of a changing economy which has seen many manufacturing plants close in the face of global competition."

Obama later discussed the economy before a wider audience, when he became the first sitting president to appear on CBS' television's "Late Show with David Letterman."

At the United Nations, Obama will delve into issues like Middle East peace, the strategy for the Afghanistan war and nuclear non-proliferation.

The agenda at the summit of the Group of 20 big economies in Pittsburgh will focus on overhauling global financial regulation and fixing long-term imbalances in the world economy.

Those agenda items are high priorities for Obama, but his schedule this week reflects a recognition that jobs, the costs of college tuition and other pocketbook issues are paramount for the U.S. public.

Obama has been struggling to push up his approval ratings, which have tumbled amid a rancorous debate on his plan for healthcare reform and accusations by critics that his policies would lead to too much government meddling in the economy.

The Letterman show mixed comedy with weightier issues.

Asked about former President Jimmy Carter's comment that some of the sharp criticisms aimed at Obama seemed to reflect racism, Obama deadpanned, "I think it's important to realize that I was actually black before the election."

On the economy, Obama offered a cautious prognosis.

"It is improving. We've seen some stabilizing, the financial markets aren't in meltdown. But we are not out of the woods yet," he said.

White House officials have indicated frustration that Obama is not getting more credit for helping to pull financial markets back from the brink and stabilizing the US economy, which was in freefall when he took office in January.

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