Sen. Tom Cotton, R-Ark.,has expressed support for presumptive GOP nominee Donald Trump, but on NBC’s “Meet the Press” his support seemed less than enthusiastic. “Maybe I don't just demonstrate enthusiasm much in life,” he said with a smile, “especially in such dangerous times as these.”

Cotton, an Army veteran and member of the Senate Armed Services Committee, has been a sharp critic of Hillary Clinton’s foreign policy. “She has been responsible for many of the worst decisions of the Obama administration,” he said.

He continued his case against Clinton, “She was literally present when we pressed the reset button with Russia just a few months after Russia had invaded Georgia. In 2011, when our commanders said they needed more troops in Iraq and when every Iraqi leader wanted a new agreement to keep those troops there, she couldn't achieve that even though she was Secretary of State. And she was the strongest advocate inside the Obama administration for the Libyan misadventure which has now led to the strongest ISIS cell around the world.”

Yet, when asked repeatedly, Cotton declined to make a positive case for why Donald Trump is the better candidate. “Donald Trump can ultimately make the case for himself,” he said.

“Donald Trump, like most Americans, like most Republicans, believe in protecting America's core national interests. He believes as do I, as do most Americans, that we aren't yet doing enough to take the fight to the Islamic State,” he added.

Asked how he squares Donald Trump’s foreign policy worldview with his own, Cotton did not directly answer, instead indicating a president from either party could be stopped by the Senate.

“It’s important to remember that whatever the presidential candidates of either party say, they will have to interact with the United States Congress, particularly the Senate, when it comes to crafting policy…we play an important role. And I’m going to continue to play that role whoever is president,” he replied.