In a new foreign policy interview, Republican presidential nominee Donald Trump warned that his opponent Hillary Clinton’s plans for military action in Syria if elected would lead to World War Three because of the risk of the conflict quickly including Russia.

Trump warned that Clinton’s calls for military action against Syria weren’t feasible, warning “you’re fighting Syria, Russia and Iran” with such an operation, adding that Russia is a country with a massive arsenal of nuclear weapons.

In the past two debates, Clinton has made much of her Syria plans involving imposing a “no-fly zone” over the country, claiming that the operation would give the US “military leverage” over Russia in the negotiation of an eventual deal over regime change.

Pentagon officials have sounded similar concerns, with Gen. Joe Dunford, the chairman of the Joint Chiefs of Staff, warning that even establishing a no-fly zone would require the US to commit massive military force to Syria, and would have a major potential to lead to direct military conflict with Russia.

Trump, by contrast, has argued that the war should be focused on defeating ISIS instead of defeating the Syrian government. This same debate has been ongoing within the Obama Administration for months.

As usual, the Clinton campaign did not address the substance of the concerns, but rather condemned Trump, insisting he is “parroting Putin” by arguing against a war with Russia, and that he is “unfit” for the presidency.