Phillip Hayes, a spokesman for the American Sugar Alliance, said in an email, "The U.S. negotiating team, led by Commerce Secretary Ross, should be commended for their hard work to bring Mexico's subsidized sugar industry into compliance with U.S. trade laws".
But complaints from U.S. sugar concerns continued, and Washington and Mexico City reopened talks a year ago.
Guajardo appeared in an interview on CNBC describing the talks, saying how negotiators dealt with "minor technicalities" overnight.
He did not elaborate on what action the Commerce Department would take if there were no final agreement with the US producers.
Ross said he hopes the sugar industry will support the deal once it is finalized in the coming days.
The deal, which was still coming together on Tuesday morning, will reduce the share of refined sugar that Mexico can export to the United States but maintain Mexico's overall access to the USA sugar market, Guajardo said on Mexican radio.
Some Mexican customers of U.S.ag commodities have already indicated they're nervous about a redo of NAFTA.
A trade group that represents a coalition of US sugar buyers and other firms that are critics of the USA program said the deal favored the interests of US sugar producers, and estimated the cost to the consumers in higher prices for food, drinks and confectionary at around $1 billion.
An agreement in Washington would help avert stiff USA duties and Mexican retaliation on imports of American high-fructose corn syrup before wider trade talks expected in August.
Ross said the extra time was necessary to complete the last technical consultations in the deal. Another Mexican official and a US industry source said the USA sugar industry later came back with additional demands outside of the terms agreed on earlier.
Those demands included changes to a provision of first refusal right which would give Mexico the right to sell refiners in the USA any additional sugar necessary beyond the agreed to quotas.
The deal would mark the culmination of a multi-year dispute between the countries over sugar, after USA groups in 2014 asked the government for protection from subsidized exports from Mexico.
Cooler heads prevailed in heated trade talks between the US and Mexico - for now.
U.S. Agriculture Secretary Sonny Perdue says the agreement "sets an important tone of good faith leading up to the renegotiation of the North American Free Trade Agreement".
The same source said that ASR Group a cane refiner that is a partnership with the Fanjul family which is politically connected has been active in raising the requirements. U.S. President Donald Trump has pledged to re-negotiate the treaty.