(Reuters) - Irish Prime Minister Leo Varadkar held a phone call with U.S. President Donald Trump in which he discussed migration and Britain’s exit from the European Union, the Irish government said in a statement on Tuesday. “Particular topics discussed included migration, Brexit and the movement of goods and citizens across the border, climate change, free trade, Irish inward investment in the United States, and the undocumented Irish,” the statement said, as well as the Northern Irish peace process. The border between Northern Ireland, which is part of the United Kingdom, and the Republic of Ireland, an EU member, will become the only land frontier between the UK and the EU after Britain exits the bloc in March 2019. 