North America Free Trade Agreement talks are now expected to blow past the new year deadline that the United States and Mexican negotiators had hoped they would be able to meet.

Schedulers are looking to book additional talks in February 2018, while stretching the rounds of talks already planned.

A source with direct knowledge of the talks says the standard five days per round could be extended to seven, or even 10 days, depending on progress at the negotiating table.

Talks have been held at a hectic pace, scheduled approximately two weeks apart, since the U.S. and Mexico want negotiations wrapped up before 2018, when elections are scheduled in both countries.

The U.S. has midterm elections in the fall, while Mexico has a federal election next summer.

Creating additional rounds, and lengthening existing ones, is not expected to boost morale at the negotiating table.

The latest talks became increasingly difficult after the U.S. made protectionist demands that Canada and Mexico have said are "non-starters."

A number of American demands have crossed so-called red lines for Canada:

Increased U.S. content in the auto sector.

A five-year sunset clause on NAFTA.

Restrictions on government procurement.

Gutting NAFTA's dispute resolution mechanism.

Increased access to the Canadian dairy market.

Instead of one or two poison pills, the U.S. has dumped a handful onto the negotiating table.

'They don't like what they are doing'

The source says it appears some members of the U.S. delegation are uncomfortable with the demands they are presenting, which appear to have been dictated to them by the Trump administration.

"They don't like what they are doing," says the source, who was not authorized to speak about the talks on the record.

There also appears to be a sense of confusion about the overall U.S. vision for NAFTA and who is really running the show.

Minister of Foreign Affairs Chrystia Freeland, United States Trade Representative Robert Lighthizer, centre, and Mexico's Economy Minister Ildefonso Guajardo Villarreal talk together before a dinner at the National Arts Centre, last month in Ottawa. (Justin Tang/Canadian Press)

U.S. Trade Representative Robert Lighthizer is President Donald Trump's point person on NAFTA, but he was not included in a key Oval Office meeting with Prime Minister Justin Trudeau last week, when Trudeau pressed Trump to support of the trilateral trade agreement.

Instead, Wilbur Ross, the secretary of commerce, was at Trump's side for the conversation.

Lighthizer will attend a meeting with his counterparts Wednesday, with Foreign Affairs Minister Chrystia Freeland and Mexico's Economy Secretary Ildefonso Guajardo.

All three trade czars will take part in a series of meetings, including a working lunch, before making closing remarks at a press conference.