WASHINGTON (AFP) -- President Donald Trump on Saturday touted his partial, unsigned trade deal with China as a major achievement and the best deal US farmers have ever secured.

"WOW, the Farmers really hit pay dirt," Trump tweeted.

Friday's initial agreement, which marks a halt in the 18-month trade war, calls for a huge increase in China's purchases of US farm products.

It also covers intellectual property, financial services and currencies.

Trump said Friday evening the deal calls for China to increase its imports of US farms goods to $40-50 billion a year -- more than double the level of 2017.

The US will also hold off on a massive tariff increase planned for next week.

But the accord will take weeks to finalize, and the details are not clear.

Nor will it roll back tariffs already in place on hundreds of billions of dollars in two-way trade.

The two sides have touted progress in their trade talks before, only to see things come apart later.

Still, Trump cried victory in a series of tweets Saturday.

"The deal I just made with China is, by far, the greatest and biggest deal ever made for our Great Patriot Farmers in the history of our Country," Trump tweeted.

He said the accord calls for such a big increase in Chinese purchases of US farm goods like soy that there is debate over whether US growers can produce enough.

"Our farmers will figure it out. Thank you China," Trump wrote.

He also said that, among other aspects, the accord calls for "16-20 Billion in Boeing Planes."

It was not clear if Trump meant new orders or previously existing ones.

Boeing declined to comment when reached by AFP. (AFP)