Bush did not say who would be made the first US envoy to the 57-nation Organisation of the Islamic Conference, in his latest bid to counter the tide of anti-Americanism in the Muslim world.
But Al Jazeera's Viviana Hurtado said he would have to be a respected American Muslim who can articulate US foreign policy, withstand criticism at home and scepticism from people in the Middle East who may see him as Bush's puppet.
In his speech marking the 50th anniversary of the Islamic Centre of Washington, Bush said that while the principles of religious freedom have been expanding elsewhere in the world, in the Middle East there had been a rise of "extremists".
"This enemy falsely claims that America is at war with Muslims and the Muslim faith, when in fact it is these radicals who are Islam's true enemy," he said.
"We must encourage more Muslim leaders to add their voices, to speak out against radical extremists who infiltrate mosques, to denounce organisations that use the veneer of Islamic belief to support and fund acts of violence."
Asked about the simplistic way of viewing the Middle East as having only either moderates or extremists, Karen Hughes, the US undersecretary of state for public diplomacy, told Al Jazeera that the distinction was to draw a clear line between those who advocate using violence and those who do not.
Anti-American sentiment has increased since the US-led invasion of Iraq and Afghanistan and Bush's past use of terms such as "crusade" and "Islamo-fascists" in referring to the "war on terror" and Iraq has angered many Muslims worldwide.