President Donald Trump has contradicted Republican leaders on some of their goals for the massive GOP tax overhaul.

House Speaker Paul Ryan joked that Trump won't be able to object to the full GOP tax bill when it's released because he'll be "in Asia."

The tax plan is set to be released on November 1, and Trump will depart on his trip two days later.

House Speaker Paul Ryan joked Thursday that there could be one big factor that stops President Donald Trump from attacking various parts of the forthcoming GOP tax bill: a roughly 12-hour time difference.

Ryan was asked if he was confident that Trump would not speak out against possibly unpopular elements of the bill, set to released on November 1, after the president rejected possible changes to 401(k)s and a border adjustment tax. The speaker said it would be fine because Trump would be half a world away.

"He's going to be in Asia, number one. No I'm kidding," Ryan said, laughing. "That was kind of a joke. I was sort of joking on that one."

Trump will leave for a 12-day, multi-country trip to Asia on November 3, two days after the tax bill's scheduled release date.

Ryan subsequently said he wasn't concerned about potential intraparty squabbles because congressional Republican leaders and White House officials have been meeting as part of the "Big Six" negotiations for months.

"So as you know with the Big Six, we worked very hard with the parameters and design decisions about what goes in to this," Ryan said. "The tax writers are working on the actual granular details and how to make the framework work and we're working very, very closely with the White House so that there will be no surprises for our partners in the White House or Senate."

But in recent days, Trump has seemed to contradict GOP leaders on Twitter regarding possible changes to retirement accounts in the tax plan.

On Friday, reports surfaced that Republicans were considering lowering the cap on contributions to traditional, tax-deferred 401(k)s to $2,400 a year from the current $18,000 for people under the age of 50.

The developments prompted backlash — and, eventually, a tweet from Trump, who on Monday promised "NO change to your 401(k)."

On Wednesday, however, Rep. Kevin Brady — one of the authors of the tax bill and the chair of the House Ways and Means Committee — left the door open to changes to retirement accounts despite Trump's tweet. Trump then said later on Wednesday that the GOP could use retirement savings changes for "negotiating" purposes.

Analysts said after the snafu that tax reform would come with difficult choices about deductions that must be cut, since the bill can only add $1.5 trillion to the federal debt over 10 years. If Trump decides to come out against some of the deduction eliminations or other ways to pay for the deficit increase, it could complicate matters for Republican tax writers.

"We think Republicans are prepared to make tough – and unpopular – decisions but they face one important obstacle: Donald J. Trump, who is already butting in, not showing the discipline required to get the bill passed," said Greg Valliere, chief strategist at Horizon Investments.