Cruz released his birth certificate amid concerns that being born in Canada could derail a possible presidential run by the tea party firebrand.
The 42-year-old gave a copy of the document to The Dallas Morning News, which posted a picture of it online Monday. It shows Cruz's birth in Calgary, Alberta, on Dec. 22, 1970, while listing his mother, Eleanor Elizabeth Wilson, as having been born in Delaware and his father, Rafael Bienvenido Cruz, as a native of Cuba.
Cruz's father was an engineer, and the couple had come to Canada as part of that country's energy boom -- although Cruz would spend most of his formative years in Houston.
Asked if additional copies of the birth certificate would be made available, Cruz spokesman Sean Rushton said several media outlets had made similar requests and that he was working on them.
In a statement issued Monday night, Cruz said "the facts of my birth are straightforward: I was born in 1970 in Calgary, Canada. Because my mother was a U.S. citizen, born in Delaware, I was a U.S. citizen by birth. When I was a kid, my Mom told me that I could choose to claim Canadian citizenship if I wanted. I got my U.S. passport in high school.
"Because I was a U.S. citizen at birth, because I left Calgary when I was 4 and have lived my entire life since then in the U.S., and because I have never taken affirmative steps to claim Canadian citizenship, I assumed that was the end of the matter," he added. "Now The Dallas Morning News says that I may technically have dual citizenship. Assuming that is true, then sure, I will renounce any Canadian citizenship. Nothing against Canada, but I'm an American by birth and as a U.S. Senator, I believe I should be only an American."
Cruz was a little-known former Texas solicitor general and veteran of George W. Bush's presidential campaign when he launched a bid to replace retiring U.S. Sen. Kay Bailey Hutchison. Spurred by a wave of grassroots support, Cruz upset mainstream GOP favorite and powerful Lt. Gov. David Dewhurst in last year's Republican primary, then coasted to victory in November.
Since taking office, he has embraced the role of Senate troublemaker, angering Democrats and even some Republicans with his outspokenness. Cruz has most recently joined with other tea party darlings in the Senate and called for partially shutting down the federal government in an attempt to block funding for the White House-backed health care law.
Cruz also has fueled speculation he could run for the White House by wowing conservative crowds during frequent trips to Iowa, which will open voting for the 2016 GOP presidential primary.
Article 2, Section 1, Clause 5 of the U.S. Constitution states that "No person except a natural born Citizen" is eligible to be president. But Cruz's office has long maintained that because his mother was an American, Cruz became a U.S. citizen at birth.
President Barack Obama, who was born to an American mother and Kenyan father, faced sharp criticism from some conservatives who claimed he wasn't an American citizen. In 2011, Obama released a copy of his birth certificate confirming his birth in Hawaii.
Cruz is a favorite of many of the same conservative groups who raised "birther" concerns about Obama, however, and questions about his eligibility to become president because he was born in Canada have not caused as much of a stir -- at least not yet.
It is legal to hold both U.S. and Canadian citizenship, but the Canadian embassy in Washington won't say how many people do so, citing privacy concerns.
Asked during a 2012 interview with The Associated Press whether he holds dual U.S. and Canadian citizenship, Cruz wouldn't answer directly, saying only: "I am a U.S. citizen."
"I was born in Canada, but I was a citizen at birth because my mother was a citizen," he said. "I have only ever had one passport and that is a U.S. passport."
Copyright 2013 The Associated Press.