The United States has moved to crack down on corporate inversions by limiting the ability of US companies with overseas parent companies to avoid paying taxes in the US.
The US Treasury Department revealed proposals that will make it harder to engage in so-called "earnings stripping" - enabling US companies to reduce their tax liability by transferring debt to their foreign owners.
Barack Obama administration published an updated strategy document including all of their plans to limit the number of inversions, something Mr Obama has previously described as economic "treason".
Ireland is included in the report as an example of country with an economy that benefits disproportionally from the profits of US companies.
It is included in a list alongside Cyprus, the Netherlands, Luxembourg, the Cayman Islands, the British Virgin Islands, the Bahamas and Bermuda.
The list, compiled by the Congressional Research Service, includes a figure stating that profits from US-controlled companies accounted for 42% of Ireland's GDP in 2010.
The White House report says it is "implausible" that the "high concentration of US profits…reflects the actual business activity of these firms rather than tax planning".
A corporate inversion is a transaction in which a US-based multinational corporation merges with a foreign corporation and the US parent company is replaced by the foreign one, which is typically located in a country with a lower tax base than the US.
The transaction substantially reduces the American company's tax bill but there is nothing illegal in the move.
Mr Obama's administration has vowed to clamp down on such procedures but it needs a change to the US tax code to close certain loopholes, which must be voted on by Congress.
According to the OECD, the US corporate tax rate is currently 11.5 percentage points higher than the OECD average.
One analysis quoted by the White House today says that "income shifting" from the US to other countries costs the US economy as much as $100 billion per annum.
With the new actions announced today, the US Treasury Department is taking action to limit inversions by "disregarding foreign parent stock attributable to recent inversions or acquisitions of US companies", which will prevent the foreign company avoiding certain inversion thresholds preventing further acquisitions.
It announced it is also targeting the process of "earnings stripping", focusing on transactions that generate large interest deductions without financing new investment in the US.
It is also changing how the Internal Revenue Service audits inverted companies, and changing due diligence and compliance requirements, and linking those requirements to tax rates.
