U.S. Sen. Ted Cruz, R-Texas, says he is giving up Canadian citizenship, a citizenship he says he was not aware he could claim. Cruz is frequently mentioned as a Republican presidential candidate in 2016. The Constitution requires the president to be a \"natural-born citizen,\" a term the document does not define. He was born in Calgary, Alberta, 42 years ago, the son of a mother with U.S. citizenship and a Cuban-born father. Cruz responded to a story Monday in The Dallas Morning News that he legally holds dual citizenship by renouncing any claim to be a Canadian, The New York Times reported. \"The Dallas Morning News says that I may technically have dual citizenship,\" Cruz, 42, said Monday. \"Assuming that is true, then, sure, I will renounce any Canadian citizenship. Nothing against Canada. As a U.S. senator. I believe I should be only an American.\" U.S. Sen. John McCain, R-Ariz., who was born in the Panama Canal Zone, where his father was serving as a Navy officer, had to deal with questions about whether he could be president when he ran in 2008. And President Obama, born in Hawaii to a U.S. mother and Kenyan father, has had to deal with \"birthers\" who say his Hawaiian birth certificate was forged despite state officials\' insistence that everything is in order.