While stumping for tax reform in North Dakota on Wednesday, President Trump promised details on a plan in two weeks.

"We're going to get into great detail in the next two weeks," Trump said during a speech at the Andeavor Corporation's refinery in Mandan. "But we're working on it with Congress right now and coming up with very exacting numbers."

Trump and his aides have long promised a detailed tax reform, only to see their plans become successively less detailed as they have worked with Republicans in Congress.

Most recently, the White House has been working toward legislation based on a joint plan with congressional Republican leaders. At this stage, though, there is not a plan but rather a set of possible combinations of provisions that they are weighing.

In recent days, GOP tax writers have emphasized that their goal is to pass legislation this year.

During his speech, Trump again laid out four broad planks for tax legislation: simplification, middle-class tax relief, lower tax rates to make businesses more competitive, and provisions to bring back the trillions of profits that corporations have earned overseas and not repatriated.

He also specifically mentioned that he aims to eliminate the estate tax and enlarge child tax credits, a venture favored by his daughter Ivanka Trump.