Some degree of optimism followed a US trade delegation home from Beijing on Wednesday, after the most comprehensive trade negotiations held yet between the world’s two largest economies since a tit-for-tat tariff battle ensued last year.

The US released a statement on the meetings, alluding to at least one potential concrete commitment on the part of China.

“The talks also focused on China’s pledge to purchase a substantial amount of agricultural, energy, manufactured goods, and other products and services from the United States,” the statement, released by the Office of the US Trade Representative, said.

That pledge, addressing a trade deficit in goods, was however mentioned only at the end of the statement which focused on the US demands for structural changes to China’s domestic policies.

There has been some indication of Chinese moves to address concerns regarding forced technology transfer, including recently proposed legislation that would bar local governments from forcing foreign firms to transfer technology or illegally restrict market access.

But a more difficult question may be whether China agrees to monitoring of such a commitment, a condition that US Trade Representative Robert Lighthizer has said is a prerequisite to any deal.

That issue was the first stressed in the statement released Wednesday, which noted that “the officials also discussed the need for any agreement to provide for complete implementation subject to ongoing verification and effective enforcement.”