This will be the first of their Pool A games that will be followed up by playing New Zealand and then the South Sea Island nation of Tonga, with the top two teams qualifying for the knock-out stages.
Commenting on the tournament, Elwood said: "Like all tournaments, the first game is pivotal. Argentina is a key game for us as they always have a strong and talented side at this level. If we can get a positive result in that game, it can put us in a good position to qualify out of our group.
"Our next game against New Zealand is a whole different challenge and with the standard of players that they have in their squad, they always seem to start these tournaments as favourites. After that we have another physical game on our hands against Tonga, so they do not get any easier for us.
"The squad has prepared really well over the last couple of months in terms of conditioning, with the emphasis on facing these physical sides in our first three games.
"The players have been excellent in their commitment and attitude during this period and I think that this will definitely stand to us. The majority of the squad now has good experience following the Six Nations championship, so that will also be a plus going into the tournament," he added.
The Ireland squad will take part in a training game against their Scotland counterparts at Ravenhill this Friday evening (kick-off 6pm) and the match will have free entry for fans to watch Elwood's team make their final preparations for the tournament.
The Under-20s will then take on an Ireland Under-23/Churchill Cup team next week to allow both sides prepare for their respective tournaments next month.
IRELAND UNDER-20 Squad (sponsored by PricewaterhouseCoopers):
Forwards (14) -
Stephen Archer (UCC/Munster)
Ben Barclay (UCD/ Leinster)
Stephen Douglas (Ballymena/Ulster)
Michael Entwistle (Ballymena/Ulster)
Kieran Essex (UL Bohemians/Munster)
Jason Harris-Wright (Greystones/Leinster)
Conor Higgins (Buccaneers/Connacht)
Paul Karayiannis (Queen's University/Ulster)
Patrick Mallon (Lansdowne/Leinster)
Ian Nagle (UCC/Munster)
David Nolan (Galwegians/Connacht)
Paul Ryan (Blackrock College/Leinster) (capt)
James Sandford (Queen's University/Ulster)
Eoin Sheriff (Lansdowne/Leinster)
Backs (12) -
Eoin O'Malley (Old Belvedere/Leinster)
Conor Cleary (Greystones/Leinster)
Chris Cochrane (Queen's University/Ulster)
Martin Dufficy (Dublin University/Leinster)
David Kearney (Lansdowne/Leinster)
Ian Madigan (Blackrock College/Leinster)
David Moore (Blackrock College/Leinster)
Niall Morris (Blackrock College/Leinster)
Ian Porter (Queen's University/Ulster)
Sean Scanlon (UCC/Munster)
Eamonn Sheridan (Lansdowne/Leinster)
Jamie Smith (Ballymena/Ulster)
Manager - Phil Orr
Coach - Eric Elwood
Assistant Coach - Dan McFarland
Ireland IRB Junior World Championship Fixtures (Pool A):
Argentina Under-20 v Ireland Under-20, Friday, June 6, Cardiff Arms Park, Cardiff, 7pm
Ireland Under-20 v New Zealand Under-20, Tuesday, June 10, Cardiff Arms Park, Cardiff, 9.10pm
Tonga Under-20 v Ireland Under-20, Saturday, June 14, Cardiff Arms Park, Cardiff, 3pm
All information and results will be available on http://www.irb.com/ throughout the tournament as well as including comprehensive media service. There will also be comprehensive coverage on IrishRugby.ie.