The Florida Republican sharply rebuked Trump's arguments that the U.S. should scale down its global presence in favor of focusing on domestic problems and argued that U.S. engagement around the world remains key to a healthy U.S. economy and national security. Rubio, speaking at the Hudson Institute here, framed his remarks in the context of the presidential race and pointed to policies Trump has adopted as central to his presidential campaign.
"It's a lot easier to say let's walk away. It's a lot easier to say for example, why do we give all this money to NATO and these other people do not? It's easier to say that than to explain what would happen if you didn't," Rubio said, alluding to Trump's views on the North Atlantic Treaty Organization. "While it is true that there are certainly consequences and complexities presented by our engagement, I still think a world without our engagement is not a world we want to live in."
"If we are not engaged in the world, the price will pay will be much higher in the long run than the price we pay to be engaged," he added.
Rubio's remarks follow his announcement
that he has no interest in serving as Trump's running mate. On Tuesday, Rubio, who just returned from a tour of Middle Eastern countries, pointed to a "sense that the whole U.S. engagement with the world is a one-way street," which Trump has been tapping into throughout his campaign.
"The natural instinct is to say, 'All this world just brings us (is) grief,'" Rubio said. "It just doesn't work."
Trump, while rejecting criticism that he is an isolationist, has argued that U.S. allies -- including Japan, South Korea and Saudi Arabia -- must begin funding a larger share of the U.S. military's presence around the globe or risk losing U.S military protection in their region. In a foreign policy speech late last month, Trump outlined his foreign policy vision with the slogan "America First."
But Rubio on Tuesday challenged those who believe the U.S. does not gain from its global footprint to consider the advances countries such as Japan and South Korea have made in recent decades as a result of a strong U.S. presence in the region.
"At the end of the day, the products we invent have to be sold somewhere," Rubio said.
Asked directly about Trump, Rubio said he stands by his "policy differences and reservations" about Trump's campaign, but said he would not spend his time knocking the presumptive GOP nominee.
"I don't see myself as the guy who's going to spend the next six months taking shots at him," Rubio said, adding that he "respects" and "accepts" Trump's nomination by Republican primary voters.
"That's not going to change the reservations I have about this campaign," he added.