Bloomberg reports on the matter

US China

Saying that the US is demanding that China detail how it plans to reach as much as $50 billion in agricultural purchases, and that such a demand has become a sticking point in negotiations, citing people familiar with the matter.

It is said that China is resisting a proposal from the US that it provide monthly, quarterly and annual targets for purchases while insisting that both sides must agree to rollback tariffs in phases if a trade deal is reached.

Just a couple more details surfacing on trade talks but this is exactly the same story as what we heard from the WSJ overnight here.