The Longitude festival is being policed appropriately following a normal security risk assessment according to Gardaí.
A security alert on the US Embassy's website said that "reports indicate a potential for violence" at the festival which is taking place in Marley Park in Dublin.
The website states that local police are aware of the "threat" and will conduct comprehensive bag and person searches.
It also said that police have increased event security and are monitoring the situation.
In response, the Garda Press Office has said that it does not comment on statements made by third parties and the festival is being policed appropriately following normal security risk assessment.
The US Embassy website directs its citizens to avoid Marlay Park and the areas surrounding the park and to exercise caution if in the vicinity.
It asks people to monitor local media for updates, be aware of surroundings, to keep a low profile and to notify friends and family of their safety.
A spokesperson for the US Embassy said he had no further information beyond what was issued in the Security Notice.
Gardaí say no incidents have been reported to date and a full, comprehensive policing plan is available on www.garda.ie
A number of rappers are playing at the festival which began this afternoon shortly before 4pm and will conclude on Sunday.
Festival promoter MCD has not commented on the security alert so far.