The Government is being 'extremely lax' in the rules that apply to Americans coming to Ireland, according to Róisín Shortall.
The Social Democrats co-leader is calling on the Government to take action, saying Ireland is the only EU country allowing US tourists in despite the surge in coronavirus cases in many states there.
Record numbers of new coronavirus cases are being reported in parts of the US, with Florida reporting 15,000 cases yesterday alone.
Despite the increase, a number of airlines have resumed flights between the US and Ireland.
Speaking on Newstalk Breakfast, Deputy Shortall highlighted that there's no legal basis behind the advice for people to self-quarantine for 14 days when they arrive here.
She said: "There is a legal requirement to fill out one of these passenger locator forms... but in terms of the self-isolation there's no legal requirement.
"Effectively that means people can come in here from any country that has flights coming in and move around the country, without really any restriction at all."
Deputy Shortall said it's a 'dangerous situation', as the system doesn't differentiate between countries with low levels of the virus and areas still facing significant challenges.
She raised concerns about the delay in the Government publishing a 'green list' of countries deemed safe to travel to - noting such a system seems to be 'working reasonably well' elsewhere in Europe.
She observed: "We are the only EU country that allows American visitors to come in at the moment. Why are so out of line with the rest of Europe? We're clearly engaged in high-risk activity here.
"There's been a lot of complacency I think over the last few weeks.
"The alarm bells are being sounded by the health authorities, and we ignore those at our peril."
She stressed that the last thing anyone wants is to experience a second wave of the virus or another lockdown.
She added: "Everyone would love a holiday, especially a holiday in the sun - people are putting those off in the public interest.
"Yet they're seeing the Government being extremely lax in the rules that apply to Americans in particular. We need action on this."
The Government is expected to meet later this week to discuss travel restrictions, having previously said the 'green list' will be published by July 20th.
