U.S. President Donald Trump waded in the tax cuts debates on Monday by urging lawmakers in the Republican-controlled Congress to cut the top income tax rate to 35 percent.

　　Members of the U.S. House of Representatives and Senate have been debating their respective tax cuts plans since last week, hoping to bridge differences and pass the bill by the end of the year.

　　"I am proud of the Rep. House & Senate for working so hard on cutting taxes (& reform.) We're getting close!" Trump wrote in a Twitter post Monday.

　　The tax cuts bill under discussion in the House reduces personal income tax brackets from seven to four, but leaves the 39.6 percent top rate unchanged. The Senate proposal calls for keeping the existing seven tax brackets and cutting the top tax rate to 38.5 percent.

　　By analyzing the House version of tax cut bill, Tax Policy Center, an independent think tank, found that the current plan disproportionally favored the rich. "The largest cuts, in dollars and as a percentage of after-tax income, would accrue to higher-income households," it said in a report published last week.

　　Besides, Republicans have to find ways to fund the tax cuts. The House tax bill would add US$1.7 trillion to the national debt over the next 10 years, according to the Congressional Budget Office, while the Republicans only allowed themselves up to US$1.5 trillion of deficit increases over a decade.