This was a major campaign pledge that remains short on detail and a long way from becoming law.
The president has named Ireland as one of America's global competitors, as he outlined plans for tax reforms.
The Trump administration said his tax reform plan for April 2018 was to slash the number of tax brackets from seven to three and bring the corporate tax rate down to 15%.
Chuck Schumer of NY, the Democratic leader, said in a conference call organized by progressive groups planning an intensive campaign to oppose Trump's tax-cutting initiative.
Representative Jason Smith serves on the Ways and Means committee; tax writing is what they do, and he says they've been working with the president to simplify the tax code.
"I don't want to be disappointed by Congress, do you understand?"
"America remains stuck in the past when it comes to taxing business 35 to 40 percent", Trump said.More news: Novartis gains historic FDA approval for CAR-T leukemia therapy
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Trump then explained that he is embracing four principles of tax reform.
"We are relying on and anticipating a very busy September at the White House".
Reports are Trump is hoping to bring down taxes for all while closing loopholes.
The President classified his ideas as "pro-American tax reform" that will allow companies to hire in the US and expand at home, not overseas. "I'm calling on congress to provide a level playing field for our workers and our companies. and to put more money into the pockets of everyday hard-working people and also into the pockets of our companies so they can continue to grow and expand".
He spoke in broad strokes, saying that it was a "monumental thing that happened" when Ronald Reagan authorized lowering the corporate tax rate to 34 percent in 1986. The primary challenge is to propose tax reform that could include tax cuts for firms and high-income earners.
"There's no evidence whatsoever that the administration or Republicans in Congress are prepared to get rid of enough deductions to get anywhere close to paying for a tax cut for that magnitude", Bartlett said.
But he also made clear that, as he had done with health care reform, he planned to leave much of the actual planning to Congress.
"It seems that this is an area where Trump can turn the page with Congress", Delehanty said in an interview.
Ideally, the corporate rate should be 15 percent, he said, or "we can not restore our wealth". "And if she doesn't do it for you, you have to vote her out of office", Trump said to applause.