President Barack Obama says a "network of misinformation" and rumors are to blame for confusion about his faith.

A recent poll found nearly one if five Americans believe the president is a Muslim, despite him often declaring that he's a Christian.

In an interview that aired Sunday on NBC's "Nightly News," Obama said he's faced questions about his upbringing since the presidential campaign, but isn't concerned about the unfounded claims.

"I can't spend all my time with my birth certificate plastered on my forehead... the facts are the facts," Obama said. "It's not something that I can... spend all my time worrying about [and] I don't think the American people want me to spend my time worrying about it."

A group of more than 70 pastors and Christian leaders also recently came to Obama's defense, criticizing the "misinterpretation" of his faith.

They are urging the media and other faith and political leaders "to offer no further support or airtime" to those who question the president's background.