WEBSTER CITY, Iowa — U.S. Sen. Ted Cruz is tying questions about his citizenship, most recently raised by billionaire Donald Trump, to another foe in the GOP presidential field: Senate colleague Marco Rubio.

Cruz made the connection Thursday afternoon when asked about the statement by another senator, John McCain, that he does not know if Cruz is eligible to become president. Cruz was born in Canada to a father from Cuba and a mother from the United States. 

“It is no surprise. Everybody knows that John McCain is going to endorse Marco Rubio,” Cruz told reporters before a stop in Webster City. “Their foreign policies are almost identical. Their immigration policy is identical. And so it’s no surprise that people who are supporting other candidates are going to jump on silly attacks.”

In recent days, Trump has repeatedly wondered aloud if Cruz’s Canadian birth would prove problematic if he became the nominee. The billionaire has advised Cruz to settle the matter in court as soon as possible, something Cruz flatly said Thursday he would not consider.

The Texas Tribune thanks its sponsors. Become one.

“It’s not going to happen, and I’m not going to be taking legal advice anytime soon from Donald Trump,” the Texan told reporters.

Cruz’s decision to involve Rubio drags the Florida senator into a Trump-fueled debate that has been raging for the past few days. For weeks, Cruz and Rubio have been trading barbs over their views on foreign policy and immigration, areas where Cruz has argued Rubio is much more aligned with the GOP establishment than he is.