U.S. President Barack Obama has said the United States continues to be the world's leading stabilizing force.
In his weekly address on September 27, Obama said "American leadership is the one constant in an uncertain world."
Obama said the United States has mobilized to tackle some of the world's most pressing challenges.
He highlighted America's leading role in mobilizing and pursuing an international air campaign to "degrade and ultimately destroy" the Islamic State radical group, as well as U.S. efforts to rally the world against what he called the "Russian aggression in Ukraine."
Obama also described America's actions to contain and combat the Ebola epidemic in West Africa, which has claimed more than 3,000 lives since last December.
He said the United States is deploying doctors and scientists, supported by U.S. forces, "to help corral the outbreak and pursue new treatments."
The American president said the people of the world look to the United States for leadership, concluding, "And we welcome that responsibility."