US President Donald Trump will attend a G7 summit in Italy this May, the White House said Saturday, in what could be his first visit to Europe as US president.

After a call with Italian Prime Minister Paolo Gentiloni, the White House said Mr Trump would attend the meeting of seven leading industrialised economies in Taormina, Sicily.

Mr Trump's election has caused fissures in the trans-Atlantic relationship that have not been seen since George W Bush's invasion of Iraq.

Many European governments are concerned about Mr Trump's apparent backing for nationalist and populist movements on the continent and fear being wedged between a hostile United States and a hostile Russia.

Mr Trump has done little the ease those fears, meeting figures who oppose the European Union and questioning NATO's relevance.

For 75 years, the trans-Atlantic alliance has underpinned global security.

During the call, the White House said Mr Trump "reiterated the US commitment to NATO and emphasised the importance of all NATO allies sharing the monetary burden of defence spending".

Vice President Mike Pence is expected to visit a security conference in Munich and Brussels, home of the EU and NATO, later this month, in a bid to clear the air.

Meanwhile, the possibility of the Taoiseach inviting Mr Trump to Ireland has not been ruled out according to senior government sources.

However, it is not regarded as a government priority just weeks out from the visit to the White House.

Instead, the Government wants to keep the focus on a campaign to regularise the 50,000 undocumented Irish people in the US.

It is understood a final decision on whether or not to invite Mr Trump to Ireland might not be taken until the day of the White House visit next month.

But Fianna Fáil TD Michael McGrath said today the Taoiseach should meet the US president but warned against having "an invitation in the pocket for a return visit".