GOP Sen. John McCain (Ariz.) on Friday said that if President Trump isn't prepared to hold Russian President Vladimir Putin "accountable" for aggression toward the U.S. then he should cancel their meeting next week. "President Trump must be willing to confront Putin from a position of strength and demonstrate that there will be a serious price to pay for his ongoing aggression towards the United States and democracies around the world. If President Trump is not prepared to hold Putin accountable, the summit in Helsinki should not move forward," McCain said in a statement.