In a case that could set new limits on the federal government’s authority to impose bans on travel to rogue states, a judge in Manhattan is considering whether to throw out a $6,700 fine assessed by the Treasury Department against a Methodist pastor who traveled to Iraq in early 2003 to protest the impending American-led invasion.

The pastor, the Reverend Frederick Boyle, 58, of Caldwell, N.J., claims that the travel ban violates his right to free speech and his right to practice his religion. During lively oral arguments yesterday in federal court, a lawyer for Rev. Boyle, Jonathan Hafetz, said the trip to Iraq was a “reflection of his most deeply held political beliefs.”

An assistant U.S. attorney, Ross Morrison, said the travel ban, which was in effect for more than a decade of Saddam Hussein’s rule, did not implicate the First Amendment because it “regulates action, not speech.”

“There was no reason the plaintiff could not have expressed his opposition to the war somewhere else,” Mr. Morrison said.

The judge hearing the case, Donald Pogue of the U.S. Court of International Trade, did not appear entirely won over by that argument. The judge asked a question suggesting that travel to some specific locations could count as religious or political expression.

“Would it matter if the place were instead Bethlehem?” Judge Pogue asked Mr. Morrison.

The travel ban in question did not explicitly outlaw travel to Iraq, but it did outlaw spending money there on expenses incidental to travel, such as airfare and hotel and food expenses.

Judge Pogue did not issue a ruling yesterday.