Ireland is the number one destination for US foreign direct investment, according to a new report.
The study was published as US technology giant Microsoft announced it is to invest €134m a new campus building in south Dublin, marking the 30th anniversary of the company's presence here.
The report, commissioned by the American Chamber of Commerce Ireland, highlighted that 130,000 people are now employed by 700 US companies.
And those companies have invested more than $277bn in Ireland since 1990.
Report author and US economist Joseph Quinlan predicted Ireland will continue to benefit from the strength of the relationship.
"The race to remain globally competitive never ends. Unlike many nations in Europe, Ireland understands this dynamic all too well," Mr Quinlan said.
"Rising to the challenge is something Ireland excels at, with the nation's economic rebound in the past year just one more piece of evidence of Ireland's dynamic economic character."
The report found that the output from US companies here now exceeds $80bn per year.
Exports from US firms based here are four times higher than from American firms in China.
US investment to Ireland surged in the first nine months of 2014, increasing by 42pc to $37bn.
US direct investment stock in Ireland totalled a record $240bn in 2013, a greater investment stake than Germany and France combined at $196bn.
Ireland's overall investment position in the US totalled a record $26.2bn in 2013.
The report came as Microsoft announced that it was investing €134m in a new campus building at the South County Business Park in Leopardstown, bringing the company's 1,200-strong Irish team under the one roof.
It means that developers, engineers, finance and operations professionals, as well as the sales, marketing and services teams, will work alongside each other.
Taoiseach Enda Kenny described the investment as "truly significant".
The new campus will be located in a wooded setting, backing on to Leopardstown racecourse.
It will have a running and walking trail around the perimeter of the site as well as rooftop terraces looking over the trees to the race track on one side and the mountains on the other.
The total floor area of the new building will be around 34,554sq m over a basement of around 13,738 sq m. The site is just under three hectares.
Cathriona Hallahan, Microsoft Ireland managing director, said it was fitting to make the investment in the year marking the company's 30th anniversary here.
"Having grown from a small manufacturing facility with less than 100 people in 1985 to what we are today, we have a strong track record of continual investment in Ireland," Ms Hallahan said.
"Dublin is now home to a number of European and global teams and groups as well as to the first data centre located outside the United Scales - a facility that has grown rapidly over the past five years.
"The €134m investment in a modern home for our team underpins our long term commitment to Ireland."