WATCH: Full report by UTV's Political Correspondent, Vicki Hawthorne:
Foreign Secretary James Cleverly has said he will be "meeting Irish politicians ... when I go to Ireland" after talks in Belfast descended into chaos with both Sinn Fein and the SDLP pulling out at the last minute.
Sinn Fein president Mary Lou McDonald said she was not allowed to attend.
Mrs McDonald accused the government of "Tory petulance" and said the situation was "bizarre and unprecedented".
The SDLP said "it was an error by the UK Government and the NIO (Northern Ireland Office)" to exclude Ms McDonald.
WATCH: Full analysis from UTV's Political Editor Tracey Magee:
The talks, which included Northern Ireland Secretary Chris Heaton-Harris , were to discuss issues around the protocol and also focused on the Stormont power-sharing crisis.
The meeting was overshadowed by the row.
Mr Cleverly stressed the meeting was to hear from political representatives in Northern Ireland and he would meet Irish politicians when he goes to Ireland in the near future.
During a visit to Saintfield Garden Centre on Wednesday afternoon he said: "Sinn Fein were very welcome.
"My meeting ... was to meet with the elected representatives of the people of Northern Ireland.
"I will of course be going to Ireland in the near future and I'll be meeting Irish politicians, but I very much wanted to hear from representatives of Northern Ireland.
"Michelle O'Neill was invited, as was her deputy. They chose not to come but it was a very useful meeting and I did get to hear voices that had concerns, serious concerns, about the protocol, the impact it is having on people and businesses in Northern Ireland."
The meeting went ahead with the DUP and UUP and Alliance party present. They voiced their disappointment over the Sinn Fein and SDLP absence.
A UK Government spokesman added: "This meeting is for Northern Ireland politicians to talk through issues around the Northern Ireland Protocol with SOSNI (Secretary of State for Northern Ireland) and the UK Foreign Secretary.
"The leader of Sinn Fein in the Assembly (Michelle O'Neill) was invited and remains invited. "Her attendance is a matter for Sinn Fein but she was not excluded."
Speaking after the meeting, DUP leader Sir Jeffrey Donaldson said he did not want to get drawn into the row.
He said: "That is a matter between the Northern Ireland Office and Sinn Fein.
"My understanding is the NIO (Northern Ireland Office) didn't exclude any party.
"There was an issue around the protocol of Mary Lou McDonald meeting the Foreign Secretary ahead of the Foreign Secretary meeting his counterpart in Dublin.
"That is not a matter for me. I am not going to get drawn into this.
"It is better when all parties are at the table. I want to see all parties in Northern Ireland putting their views across, particularly to the Foreign Secretary.
"I hope next time the parties will be back at the table."
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