Senate Dems slam ConocoPhillips CEO over company's 'un-American' comment

"Nothing was intended to be personally directed to you or any other senators or colleagues or anyone," Mulva said.

But Menendez said he wasn't satisfied by Mulva's response.

"The bottom line is that you are unwilling to apologize for your company’s statement, so I’ll continue to take offense to it," Menendez said.

ConocoPhillips released a statement Wednesday blasting the proposal to slash the tax breaks that was headlined, "ConocoPhillips Highlights Solid Results and Raises Concerns Over Un-American Tax Proposals at Annual Meeting of Shareholders.”

Mulva, in the statement, said:

“Not only would increased taxes cost jobs, raise consumer prices and shrink government revenue, but they would also hamper our ability to remain competitive and reinvest in jobs, new energy technologies and resources in the United States and internationally.”

Pointing to the statement, Menendez called for a public apology.

“For ConocoPhillips to question the patriotism of those elected officials who believe that they do not deserve billions of dollars in wasteful subsidies is simply beyond the pale. I expect an apology from the CEO tomorrow at tomorrow’s hearing. It is simply not acceptable,” he said.

Sen. Charles Schumer (D-N.Y.) at Thursday's hearing also blasted Mulva for his statements.

“You'd be likelier to see a unicorn in this hearing room than Americans [who] believe you need these subsidies," he said.

Schumer asked the other four oil company CEOs testifying at the hearing to raise their hands if they believe that opposing the tax breaks is "un-American." None of the CEOs raised their hands.