Gerry Adams has called for the "full normalisation" of relations between the US and Sinn Féin after he was denied entry to a St Patrick's day reception in the White House.

Mr Adams arrived for the event yesterday with other Sinn Féin personnel including the party's Vice President Mary Lou McDonald and Martin McGuinness.

Mr Adams was pulled aside from the other Sinn Féin members as the White House security personnel examined his documents.

After waiting 90 minutes and seeing no movement in the effort to gain entry, Mr Adams decided to leave.

The US Secret Service later apologised, and blamed an "administrative input error".

Gerry Adams said yesterday: "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 followed up that statement today, saying: "I want to welcome the letter from the Congressional members to the White House in which they express their outrage over the refusal to allow me access to the St Patrick’s Day celebrations at the White House on Tuesday evening."

He said the "constant additional security processes and delays" which Sinn Féin representatives undergo had "long been a cause of concern", which the party had raised privately in the past.

He said he had now urged the US State Department to review their approach to Sinn Féin representatives visiting the USA and to "fulfil the commitment of the Clinton administration 20 years ago to normalise relations between the US administration and Sinn Féin".

Mr Adams said his party colleague Martin Ferris was delayed getting on his flight to Boston yesterday, and that when he eventually arrived on a later flight he was held for several hours.