The United States and Mexico are close to announcing a deal on sugar trade, Mexican Minister of Economy Ildefonso Guajardo said ahead of a planned news conference on Tuesday after talks went into overtime this week.

Guajardo, in an interview on CNBC, said negotiators worked on "minor technicalities" overnight and would likely unveil the agreement at the event with U.S. Commerce Secretary Wilbur Ross.

Ross and Guajardo are scheduled to make an appearance at 1:45 p.m. at the U.S. Chamber of Commerce in Washington, the U.S. Commerce Department said in a statement.

"Probably by that time we will be announcing that we have made an agreement," Guajardo said in an interview with the television network.

Ross on Monday extended the deadline for the negotiations by 24 hours to complete "final technical consultations" for a deal.

Sources on either side of the border said the U.S. sugar industry had added new demands outside of the terms agreed on earlier, despite an agreement that had already been struck between the governments.

An agreement in Washington would help avert stiff U.S. duties and Mexican retaliation on imports of American high-fructose corn syrup before wider trade talks expected in August.

A deal also would end a year of wrangling over Mexican sugar exports. The latest talks began in March, two months after President Donald Trump took office vowing a tougher line on trade to protect U.S. industry and jobs.

They are seen as a precursor to the more complex discussions on the North American Free Trade Agreement between the United States, Mexico and Canada.

By David Lawder - Reuters (Additional reporting by Susan Heavey; Editing by Chizu Nomiyama)