Updated

The U.S. economy will stay on the upswing during the Trump administration despite the warnings of critics who have a "vested interest in seeing us fail," Office of Management and Budget Director Mick Mulvaney told "Fox News Sunday."

Mulvaney specifically credited the White House's efforts to eliminate regulations, as well as the GOP-led Congress' massive tax bill, which was passed in 2017. Key provisions of the legislation took effect earlier this year.

"The things we’ve done on the deregulatory agenda, the things we’ve done on taxes, are not a sugar high," Mulvaney said. "It’s not a one-time sort of 'pop' to the system. It’s fundamentally changing the way we create wealth in this country."

Mulvaney continued: "We do think it’s sustainable in the long-term. In fact, I think we’re already starting to see some folks project that we’re gonna have maybe again at least three percent [gross domestic product growth], maybe four percent growth again this quarter."

GDP SHOWS BOOMING 4.1 PERCENT GROWTH AS TRUMP TOUTS 'AMAZING' NUMBERS

In July, a highly anticipated Commerce Department report showed the U.S. economy grew by 4.1 percent from April through June, marking the fastest quarterly economic expansion in nearly four years.

The growth was the largest since the economy's roughly 5-percent surge in the third quarter of 2014, which was the sharpest economic expansion since the third quarter of 2003.

Mulvaney rejected the nonpartisan Congressional Budget Office (CBO) assessments that GDP growth will slow. Analysts have cautioned that some of the GDP growth reported by the Commerce Department could be attributed to a surge in soybean and other exports, as international buyers purchased the goods ahead of the expected implementation of bruising retaliatory tariffs.

"Keep in mind -- all of the folks who are now saying it’s just a short-term sugar high, it’s just a blip, it’s not sustainable, including the CBO, are the same people who said it was impossible to get to three percent in the first place," Mulvaney told Fox News' Chris Wallace. "They have a vested interest in seeing us fail.

"All signs are good that we’re gonna actually get some spending bills passed before the end of the fiscal year," he added.

Mulvaney also suggested that President Trump had canceled his planned military parade in Washington, D.C. for reasons unrelated to funding.

"If the parade had been cancelled purely for fiscal reasons, I imagine I would have been in the room when that decision was made," he said. "And I wasn’t, so my guess is there were other contributing factors."

Mulvaney added that D.C. is a heavily liberal area, and suggested it would not be unreasonable to assume officials there would stand in Trump's way.

Trump, for his part, has laid the blame squarely at the feet of D.C. politicians.

"When asked to give us a price for holding a great celebratory military parade, they wanted a number so ridiculously high that I cancelled it. Never let someone hold you up!" Trump tweeted.

Fox News' Chris Wallace contributed to this report.