HOUSTON -

U.S. Senator Ted Cruz (R-Texas) visited the Texas Medical Center in Houston on Tuesday to continue his call to defund Obamacare.

Sen. Cruz is also gaining national attention for a big decision he made concerning his citizenship.

Cruz, whose father is Cuban, was born in Calgary to an American mother, and has maintained dual citizenship throughout his lifetime.

He now says he will renounce his ties to Canada, the country where he was born.

Some see the move as a sign that he plans to run for president in 2016.

"The question as raised, would I renounce my Canadian citizenship? And I said sure, of course. Why? Because I'm an American citizen by birth and as a U.S. senator I believe it makes sense for me to be only American," said Senator Cruz.

Cruz didn't discuss his future political ambitions while speaking in front of the Texas Conservative Coalition Research Institute.

His message was about the fight to end Obamacare, or the Affordable Care Act, which launches on October 1.

"The single biggest fight in Washington and, I think the most important fight, is the fight to defund Obamacare," he said.

Sen. Cruz's speech took place one day after U.S. Health and Human Services Secretary Kathleen Sebelius visited Houston to talk about the benefits of President Obama's signature healthcare law and encourage young people to enroll in the program.

Sen. Cruz had a more somber message.

He told the crowd that Obamacare is the single biggest job killer in this country and is hurting working American families.

Cruz also called for alternatives, such as allowing people to buy health care across state lines and ending the practice of linking healthcare to employment.

The Republican junior senator from Texas, who lives in Houston with his wife and two daughters, was scheduled to tour the Keystone XL pipeline after leaving town. However, that tour was canceled because of inclement weather.