Irish companies Netwatch and RelateCare are to announce 280 new jobs in the US.
The announcement will be made at an Enterprise Ireland event in Washington later today which will be attended by the Taoiseach.
Leo Varadkar is in the US for the traditional St Patrick's Day programme of events.
Tomorrow, he will meet with US President Donald Trump at the White House.
Speaking ahead of today's jobs announcement, the Taoiseach said: "Irish investment in the United States is increasing year on year and is now at an all-time high. The scale and diversity of this investment is indicative of the strength of the partnership between our two countries."
According to Enterprise Ireland, there are over 100,000 people employed in the US by Irish companies.
Ireland is now the ninth largest source of foreign direct investment into the United Sates at $146.2 billion.
Today, Irish security company Netwatch Group will announce 100 new jobs in the US.
Healthcare technology company RelateCare is also announcing that it is expanding operations within the US as well as Ireland, creating more than 180 new jobs in 2019.