U.S. President Donald Trump shakes hands with Ireland's Prime Minister (Taoiseach) Leo Varadkar at Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019.

Irish police officers pass by an anti-U.S. President Donald Trump sign as people demonstrate in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019. REUTERS/Clodagh Kilcoyne - RC1F58AB8F00

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019.

Donald Trump Jr. reacts as he visits a local pub in Doonbeg village, Ireland June 5, 2019.

Protesters are seen during an anti-U.S. President Donald Trump demonstration in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump and first lady Melania Trump arrive at Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump's son Eric reacts as he visits a local pub in Doonbeg village, Ireland June 5, 2019. REUTERS/Clodagh Kilcoyne - RC1D46454BD0

U.S. President Donald Trump's sons Eric and Donald Trump Jr. take a selfie with people during a visit to a local pub in Doonbeg village, Ireland June 5, 2019.

Protesters are seen during an anti-U.S. President Donald Trump demonstration in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump's son Eric reacts as he visits a local pub in Doonbeg village, Ireland June 5, 2019.

U.S. President Donald Trump speaks during a meeting with Ireland's Prime Minister (Taoiseach) Leo Varadkar at Shannon Airport in Shannon, Ireland, June 5, 2019.

A supporter of U.S. President Donald Trump is seen during a visit by Trump's sons Eric and Donald Trump Jr. to a local pub in Doonbeg village, Ireland June 5, 2019.

Protesters are seen during an anti-U.S. President Donald Trump demonstration in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump meets Ireland's Prime Minister (Taoiseach) Leo Varadkar at Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump meets with Ireland's Prime Minister (Taoiseach) Leo Varadkar at Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019. REUTERS/Clodagh Kilcoyne - RC19F2E75260

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019.

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019.

Protesters carry an anti-U.S. President Donald Trump flag as they demonstrate in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.

Protesters are seen holding signs during an anti-U.S. President Donald Trump demonstration in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.

A general view shows a camp set up by anti-U.S. President Donald Trump protesters outside Shannon Airport in Shannon, Ireland, June 5, 2019.

U.S. President Donald Trump's sons Eric and Donald Trump Jr. visit a local pub in Doonbeg village, Ireland June 5, 2019.

Irish police officers pass by an anti-U.S. President Donald Trump sign as people demonstrate in a camp they have set up outside Shannon Airport in Shannon, Ireland, June 5, 2019.