(Adds details from Trump interview)
WASHINGTON, Oct 23 (Reuters) - U.S. President Donald Trump on Monday dismissed the possibility of limiting popular 401(k) retirement savings plans to help pay for Republicans' sweeping tax plan and expressed doubts about adding another top bracket targeting high earners.
Trump, in an interview aired on Monday on Fox Business Network, also said he wanted tax reform to be approved by Congress before the end of the year.
The Wall Street Journal and the New York Times reported on Friday that Republicans were considering imposing a $2,400 cap on pre-tax contributions to 401(k) plans in order to generate more revenue. Taxpayers 50 years of age or older currently can contribute $24,000 to such retirement funds.
"There will be NO change to your 401(k)," Trump said in a Twitter post. "This has always been a great and popular middle class tax break that works, and it stays!"
Trump separately said he would rather not add a top tax bracket to Republicans' tax cut plan for top earners.
"It may not happen" he told Fox Business Network. "The only reason I would have (it) ... is if for any reason I feel the middle class is not being properly taken care of."
Trump's fellow Republicans are pushing to complete their tax overhaul by year's end, with the president eager for a major domestic victory before his first year in office concludes.
On Tuesday, Trump is expected to participate in Senate Republicans' weekly policy lunch. He also spoke with House Republican lawmakers on Sunday, the White House said.
Senate Majority Leader Mitch McConnell said on "Fox News Sunday" that he expected to complete tax reform by the end of the year, but Trump told Fox Business Network he would be "very disappointed if it took that long."
Trump's plan promises up to $6 trillion in tax cuts but would increase the federal deficit by $1.5 trillion over a decade. Democrats have criticized it as a giveaway to the rich and corporations that would swell the deficit.
Trump said that would only pressure them to act on taxes and that he thinks there are enough votes to pass it.
Party lawmakers differ widely on what cuts to make and are still weighing options for how to pay for them.
McConnell, speaking to CNN on Sunday, would not say whether he would back retirement fund caps, saying it was "way too early to predict the various details."
The idea of an additional top tax bracket had been floated by House of Representatives Speaker Paul Ryan. On Sunday, Trump's budget director, Mick Mulvaney, said the White House was "agnostic" about the possibility.
(Reporting by Susan Heavey; Editing by Bill Trott)