Republican presidential candidate Donald Trump's comments proposing to ban Muslims from entering the United States "endanger national security," Secretary of State John Kerry claimed on Sunday. "It exhibits an attitude by one American who is running for the highest office of our land about a willingness to discriminate against a religion," Kerry told ABC News . Trump caused an uproar in the United States last week when he called for a ban on Muslims entering the country in the wake of the massacre in San Bernardino. The presidential candidate was unapologetic, defending his comments on CNN and saying, "You're going to have many more World Trade Centers if you don't solve it - many, many more and probably beyond the World Trade Center."