Ireland's foreign minister Simon Coveney urged British Prime Minister Boris Johnson on Sunday not to introduce new post-Brexit trade laws in the coming the days that he said could undermine the peace process in Northern Ireland.
Top officials from Johnson's government have warned they might take unilateral action over the rules for goods going in and out of the British-run province, raising alarm in the European Union.
Coveney said London, Dublin and Brussels could find solutions for trade problems in Northern Ireland that have incensed pro-British politicians there.
"But sabre-rattling and grand-standing in Westminster, ratcheting up tension, is not the way to do it," he told Sky News television.
When Britain left the EU, Johnson agreed to a deal that effectively left Northern Ireland in the bloc's single market and customs union because of its open border with EU member Ireland, creating a customs border with Britain.
Coveney said he was due to talk on Monday with British Foreign Minister Liz Truss.
"There is an opportunity I hope in the next few days to get this dialogue back on track," Coveney said, urging London against "deliberately breaking international law and creating huge tension with our closest neighbours and potentially undermining a peace process by doing that."
Local elections in Northern Ireland this month led to renewed deadlock with pro-union parties opposing the so-called Northern Ireland Protocol, which sets out the trade arrangements, and pro-Irish parties supporting it.
Johnson is due to visit the province on Monday and his office said he would deliver a "tough message" to political leaders in order to get their power-sharing institutions back up and running.
Downing Street also said Johnson would say he had never suggested scrapping the Protocol which instead needed to be reformed so that it delivers on its initial aim to protect the Northern Irish peace agreements.
British business minister Kwasi Kwarteng said London had the right, under the terms of the Protocol, to take unilateral action to address trade problems and the priority for London was political stability.
"It's clear to me that without changes to the protocol, you're not going to get an assembly, you're not going to get an executive, and that undermines stability," Kwarteng told Sky.
The United States has called for continued dialogue between Britain and the EU to resolve the standoff.
(Reporting by William Schomberg; editing by David Evans)
