MLS commissioner Don Garber has always been keen on the proposed tournament between the two countries. Joe Robbins/Getty Images

The door remains open and talks are ongoing about the much-touted tournament between Liga MX and MLS sides, but finding dates for it is proving a to be a headache, according to MLS technical director Alfonso Mondelo.

"Formats have been discussed, but there is nothing concrete," said Mondelo in an interview with ESPN Digital's Ivan Canada. "We are waiting on various ideas and options. One of them is to have three, four or five teams from each league."

"The problem is finding dates that are open to insert [the tournament] into the calendars of both leagues," Mondelo continued, with reports suggesting at the end of last year that an agreement on the potential tournament was close.

Liga MX president Enrique Bonilla confirmed last November that Mexican clubs would not be involved in the Copa Libertadores this year and suggested Liga MX was open to a potential competition with MLS teams.

MLS commissioner Don Garber has consistently promoted the idea of strengthened relations between Liga MX and MLS, something Mondelo supports.

"Projects to help the growth [of MLS] are always studied and [Mexico and the United States] are two sister nations soccer-wise," Mondelo stated. "We can have that important contact due to the large Latino and Mexican audience we have that would like to see this type of competition."

"It is a win all around," said CONCACAF Champions League winner and ESPN FC analyst Herculez Gomez.

"Let's be honest, any time you have a Mexican club versus an American club, an MLS club it becomes Mexico versus the USA, no matter how you cut it. It's a great rivalry, it's a fun rivalry [and] we all want to buy into that so it's going to be good if they can do it and make it work."

If an agreement is reached and the tournament is made official, the Liga MX sides likely to be included are Club America, Chivas and Club Tijuana; the three teams that would've represented Mexico in this year's Copa Libertadores.