With higher tariffs originally scheduled to kick in Tuesday on imported goods from China now on hold, U.S. and Chinese negotiators still need to flesh out the details of a trade deal announced Friday at the White House, as President Donald Trump expressed optimism that the plan would be 'phase one' of a broader trade agreement.

"We have a great deal. We're papering it now," the President told reporters on Friday. "Over the next three or four or five weeks, hopefully it'll get finished."

"I mean, it's an incredible deal for farmers. I think they'll have to go out and buy more land and buy bigger tractors," Mr. Trump added, as officials said China had agreed to buy between $40 billion and $50 billion in U.S. agricultural products.

But other than those ball park figures on farm purchases, there were few details offered by either side on what was agreed, as the U.S. Trade Representative's office put out no statement or specifics on the agreement.

In Washington, the announcement drew immediate praise from Republican lawmakers from farm states, who have watched nervously from the sidelines as the U.S. raised tariffs to 25 percent on many Chinese goods, and China retaliated by reducing purchases of American agricultural products.

"This is excellent news, and I look forward to reviewing the specifics," said Sen. Kevin Cramer (R-ND).

"I’m encouraged by the progress announced on the China trade deal," said Sen. Ron Johnson (R-WI). "I hope it can be concluded expeditiously."

"Glad to see this great progress," tweeted Rep. Roger Marshall (R-KS).

"President Trump’s announcement to postpone the tariff hike is welcome news for American businesses, farmers, and consumers," said Myron Brilliant, a top official with the U.S. Chamber of Commerce.

But others pointed out that the progress made this past week in trade talks did not erase the tariffs and trade barriers already in place against American products, as China has reduced its purchases of U.S. products during this trade fight with President Trump.

The agreement "is a break in the clouds, but tariffs continue to cast a pall over the futures of farmers, ranchers and rural America," said Brian Kuehl with the group Farmers for Free Trade.

It wasn't immediately clear when a broader deal would be finished, or signed.

"We're at point where tariffs have continually escalated since basically spring of 2018 and I think both sides want to see if they can find a way out of this," said David Salmonsen, the top Washington lobbyist for the American Farm Bureau Federation. "So, we're encouraged that this is going on."