A minimum 20% tax on the overseas earnings of US multinationals would have an impact on Ireland, according to one expert in the area.
Ireland signed up to an OECD agreement on the introduction of a minimum corporate tax rate of 15% on the profits of the world's biggest multinationals late last year.
The proposals, which are scheduled to come into effect next year, would see Ireland forgoing its 12.5% rate, a key cornerstone of our industrial policy.
However, in a draft budget published this week, the Biden administration in the US again proposed introducing a minimum 20% rate on the overseas profits of US multinationals, which would imply a top-up of 5% on the tax that US multinationals pay here.
"The agenda is being driven by larger countries seeking to reduce the tax advantage that smaller countries can generate. If there was to be a 20% rate, that would significantly impact the gap that smaller countries can generate," Seamus Coffey, Economics lecturer at UCC, explained.
He said the 15% rate was not 'hugely detrimental' from an Irish perspective but if it was go any higher, it would be concerning.
"Crucially, we now have a principle where countries can come together and essentially dictate and control the Irish corporate tax rate. 15% mightn't be much of an issue, but if the US was to go to 20% or if the OECD agreement was to go to 18, 21 or 24%, that certainly would have an impact," he added.
Mr Coffey pointed out that the US Congress passes tax laws, which will dictate the pace and severity of any moves there.
"Ultimately, all the President can really do is sign what Congress passes. Given the arithmetic in the US Senate and the lack of unity in the Democratic Party, there has been difficulty in getting these proposals through," he said.
From a European perspective, the EU has published a draft directive for a minimum tax that EU countries are seeking agreement on.
A number of countries have objected, but Ireland has not.
France - which holds the EU presidency - is keen on striking a deal in the coming months.
However, a timeframe for the introduction of the rules globally by 2023 is regarded as being very ambitious.