Henry, who steered New Zealand to their second world title in 2011, worked with Pumas coach Santiago 'Tati' Phelan last year when Argentina made their debut in the expanded Tri-nations, their first participation in a major annual international tournament.
"It's an honour ... (for) the UAR to be able to count on the assistance of such an experienced and important person in the rugby world as Graham Henry," Manuel Galindo, head of the UAR's high performance department, said.
Henry is currently a technical adviser to John Kirwan at the Super Rugby Auckland Blues franchise, allowing him to resume the Argentina role, which caused debate in New Zealand last year when the Pumas played the All Blacks in Wellington.
"Having been a very competitive team in the 2013 Rugby Championship, this new edition of the tournament will be an even greater challenge for Argentina," Henry said.
"The Springboks, All Blacks and Wallabies will surely be stronger teams than last year. South Africa were a young team in 2012, Australia will have recovered their injured players and New Zealand seems to play better each year.
"But without doubt it will be a positive challenge, you only improve facing the best," Henry said.
Argentina finished bottom of the 2012 standings but took points off South Africa with a 16-16 draw in Mendoza and lost their matches against Australia by four and six points.
This year's championship could be Phelan's last as Pumas coach, a position he has held since Marcelo Loffreda quit after steering Argentina to third place at the 2007 World Cup in France.
"Tati has the doors open to continue but whether he does or not is a personal issue," Castillo said. "My opinion and that of the directors is that Tati and his staff should stay on."
He said Phelan, who has a contract until the end of the year, had mentioned possibly quitting for family reasons.
The UAR expects Phelan to advise it of his decision as soon as The Rugby Championship ends with the home match against Australia in Rosario on October 5.
Argentina are hopeful their greater presence on the international stage will open doors to getting a franchise in SANZAR's Super Rugby competition.
SANZAR chief executive Greg Peters has said expansion of the competition could be on the cards when the current television contract expires in 2015 and they were examining the feasibility of teams in Asia and the Americas.
"The ideal would be to have more competition at level one, like a European team or a Super Rugby franchise," said former Pumas captain Agustin Pichot, now a key player in the UAR's relations with the International Rugby Board.
"At the moment SANZAR have accepted looking into whether Argentina has the conditions to have a franchise or two."
Pichot said the UAR, whose third tier Pampas XV are in their fourth season in South Africa's Vodacom Cup which they won in 2011, are also looking for more competition at development level like sending a team to the Pacific Rim Cup to play against Tonga, Fiji, Samoa and Japan.
Before the Rugby Championship, Argentina have three Tests in the June international window, two against England and one against Georgia.
Castillo said the Pumas would play England, who will be touring without their Lions, on June 8 in the northwestern city of Salta and then at the Velez Sarsfield first division soccer ground in Buenos Aires on June 15.
They play Georgia at a venue yet to be fixed a week later.
Argentina open their Rugby Championship campaign away to South Africa on August 17.