Republican Sens. Lindsey O. Graham and John McCain said Sunday that the rapid implementation of Trump’s order banning entry into the United States for refugees, travelers and green-card holders from seven majority-Muslim countries risks harmful results and may help terrorists with recruitment efforts.

“Ultimately, we fear this executive order will become a self-inflicted wound in the fight against terrorism,” McCain and Graham wrote in a statement. “This executive order sends a signal, intended or not, that America does not want Muslims coming into our country. That is why we fear this executive order may do more to help terrorist recruitment than improve our security.”

Graham (S.C.) and McCain (Ariz.) are among the leading defense hawks in the Senate. This is not the first time the pair has opposed Trump in recent days. Last week they spoke out against Trump’s support for torture and encouraged him to rely on Secretary of Defense James Mattis, whose view is that “torture, including waterboarding, is not an effective tool for obtaining information.”

Neither senator explicitly rejected Trump’s order in the highly critical statement. But they are among a growing number of Senate Republicans raising questions about the order.

“Our government has a responsibility to defend our borders, but we must do so in a way that makes us safer and upholds all that is decent and exceptional about our nation,” the statement reads. “It is clear from the confusion at our airports across the nation that President Trump’s executive order was not properly vetted.”

They specifically criticized an element of the order that could prevent legal U.S. residents from Iraq, Iran, Sudan, Somalia, Syria, Libya and Yemen from returning to the country.

“Such a hasty process risks harmful results,” they wrote. “We should not stop green-card holders from returning to the country they call home.”