Enda Kenny might have been swapping gifts and sprigs of shamrock with Barack Obama yesterday, but another well-known politician was left outside in the cold.

After receiving his "usual invitation" to attend the annual St Patricks Day event at the White House, Gerry Adams was subsequently denied entry at the door.

According to the Irish Times, Adams waited around for 90 minutes while security "examined his passport," but decided to leave when it became clear he wasn't getting in any time soon.

Taking to Twitter this afternoon, Adams posted a picture of the invitation he had received with the caption, "Just saying."

Although he often faces increased security checks when flying due to his connections with the Irish Republican movement, he has previously attended the White House's yearly event without issue.

Sinn Féin's deputy leader Mary Lou McDonald and the North’s deputy first minister Martin McGuinness were reportedly allowed to enter the event without issue.

In a statement today, Adams described his "grave disappointment" at not being permitted to enter the premises.

"I had received my usual invitation to attend the St. Patrick’s Day celebrations in the White House and was pleased to accept.

"When I arrived the staff at the White House informed me that there was an issue of ‘security’.

"After two decades of travelling back and forth to the USA and countless meetings in the White House with successive US Presidents, this is an unacceptable development."

He also criticised the ongoing scrutiny he – and other Sinn Féin party members – face when travelling to the US.

"Some of our political representatives have been denied access to the USA while others, including myself, have to regularly go through additional searches and scrutiny when we travel to and from the USA."