People from Bulgaria and Romania will not be allowed to work freely in the 26 Counties for seven years after their two countries join the European Union next January, following a decision by the Dublin government yesterday.
The decision was announced within minutes of a similar decision by Britain.
While Bulgarian and Romanian citizens will be free to travel and live in Ireland, they will not be able to get a job without a work permit and will not qualify for social welfare.
However, the Dublin government is to encourage US immigrants to come to Ireland in return for the legalisation of Irish immigrants to the US.
"There is clear evidence to support the establishment of some form of bilateral agreement between the US and Irish governments," said the Minister for Labour Affairs Tony Killeen following a trip to New York.
Mr Killeen said that, while 30,000 to 40,000 illegal Irish immigrants were living in the US, two centuries of mass emigration to the US from Ireland because of famine and unemployment was clearly now at an end.
More than 4,300 Americans immigrated to Ireland in search of work last year, compared with 1,700 Irish people moving to the US, where more than ten per cent of the population claims Irish descent.
Mr Killeen said a jobs fair in New York showed how appealing Ireland had become in the wake of the "Celtic Tiger" boom.
"The interest expressed by Americans to come and work in Ireland was so great that a queue more than two-and-a-half blocks long formed outside the exhibition venue," he said.
"In less than 15 years, Ireland has gone from being the sick man of Europe to one of the most dynamic economies in the developed world."
Mr Killeen told the media in New York last week that Ireland would also try to lure Irish and US citizens back to Ireland where the population is now back above four million, having hit a 120-year low of 2.8 million in the 1960s.
Meanwhile, the 26-County Minister for Enterprise, Trade and Employment Micheal Martin said the decision to keep out further numbers of eastern Europeans was justified because of the foreign workers, mostly Polish, now employed here.
"The numbers have been extraordinary. This is one of the most rapid inward migrations ever experienced by any country. Other countries have taken 30 or 40 years to reach that point.
"This has created pressures in education, with housing, with traffic, with the health service. The challenge now is integration," the Minister said.