Northern Ireland has a “gateway of opportunity” following Brexit, the First Minister has said.

Arlene Foster pledged to mitigate the worst effects of the protocol requiring checks on some goods coming from Great Britain.

The DUP leader said the country had left the EU’s common policies on farming and fishing.

“What we have is a gateway of opportunity for the whole of the UK and for Northern Ireland and it is important that in this centenary year that we look forward to that and step through that gateway and take all the opportunities that are available for our people.”

She told the BBC’s Andrew Marr Show that Northern Ireland was out of the EU’s customs union.

The protocol keeps the country in the EU’s single market for goods and means it applies EU customs rules at its ports.

In four years’ time the Northern Ireland Assembly at Stormont will be able to vote on whether it wants to remain within the regulatory system set up by the Northern Ireland protocol.

Mrs Foster said: “I hope by that stage that people will see that it is much better to move out of these regulations and into the global market.”

The end of the transition period late on New Year’s Eve brought into force the different regulatory and customs arrangements to the rest of the UK.

Customs declarations and additional regulatory checks are required on goods moving from Great Britain to Northern Ireland. Trade in the other directions remains largely unfettered.

Mrs Foster claimed nationalist parties in Northern Ireland had wanted a no-deal Brexit.

Arlene Foster doesn’t care much for facts; indeed I don’t think she’s ever been interested in the 'jot & tittle' of reality

Sinn Fein’s South Down MP Chris Hazzard said: “For those of you who aren’t aware by now, Arlene Foster doesn’t care much for facts; indeed I don’t think she’s ever been interested in the ‘jot & tittle’ of reality, so let’s spell it out slowly.

“The DUP voted against every Brexit deal put to a vote at Westminster.”

SDLP leader Colum Eastwood said his party was totally against Brexit.

He added: “The DUP championed it.

“Trying to wash her hands of the new Irish Sea border – no-one will fall for it.

“This is where the DUP have led unionism.”

The full consequences of the protocol will not be felt until later in the year, as several grace periods have been agreed between the UK and EU to reduce the volume of paperwork and certifications needed in the first few months of operation.

The first affected ferry into Northern Ireland on New Year’s Day docked in Belfast at 1.45pm having sailed from Cairnryan in Scotland earlier that morning.

There was no evidence of disruption or delay.

Officials are required to conduct physical checks on a selection of roll on/roll off lorries under the terms of the protocol.

The BBC has reported that a small number of lorries have faced delays at the new border control posts because several loads of food products arrived on Friday and Saturday without the correct paperwork.

This is being viewed as a specific timing issue related to the introduction of the new processes.

A spokesman for the Department of Agriculture, Environment and Rural Affairs said: “As a result of the Northern Ireland Protocol, there are new processes in place for businesses and individuals moving animals, food, feed and plants from Great Britain to Northern Ireland.

“DAERA has been, and continues to engage with stakeholders to help them understand not only how to navigate the new systems, but what happens if there is non-compliance.

“DAERA is also engaging with the other agencies involved and seeking assurance that the new processes are being applied before hauliers arrive in Northern Ireland, so that delays are minimised.

“Northern Ireland’s chief veterinary officer, Dr Robert Huey has made it clear that while he will apply a pragmatic approach in the first week, the expectation from that point, is that businesses must arrive at points of entry having completed all the necessary paperwork and notifications.

“We urge everyone to urgently familiarise themselves with the new procedures, documents and will continue to engage with stakeholders.”