Taoiseach Enda Kenny has expressed impatience with the British government over the lack of clarity on its future relationship with the European Union.

Speaking at the end of a two-day summit in Brussels, Mr Kenny appeared to display irritation that London was still vague about what exactly its relationship will be with the EU, in particular its attitude to membership or otherwise of the EU customs union.

Asked if he believed there was some way Britain could remain inside or close to the customs union, or if British Prime Minister Theresa May had indicated her intentions during their bilateral meeting on Thursday night, Mr Kenny said: "I speak in respect of the Irish Government and the Irish people. We didn't cause this."

He added: "We have to put up with the consequences of it."

Mr Kenny continued: "In order to deal with the consequences we have to know what the relationship that's being sought by Britain is, beyond having the closest possible relationship with the EU."

The British prime minister said in her Lancaster House speech in London on 17 January that Britain would seek an "associative" relationship with the EU customs union.

She, and cabinet ministers, have also said repeatedly that they want the "closest possible" relationship with the EU's single market.

However, London has not clarified what that will mean, or how it would work.

It is understood that the Government is growing increasingly impatient with the lack of insight into Mrs May's thinking, given that it will be of vital importance to any issues around the Irish land border, and whether it is "hard" or "soft".

If Britain remains inside the customs union then it removes any need for customs checks between Northern Ireland and the Republic.

However, if it finally declares that it will be outside the customs union, then it will be subject to the EU's common external tariff.

That would mean tariff duties on goods passing between Ireland and Britain, and Northern Ireland and the Republic.

There is still no hint from Mrs May as to when she will trigger Article 50 of the Lisbon Treaty in order to start the process of leaving the EU, and by extension, bring about a long-term trading relationship between the UK and the EU.

Mr Kenny asked Mrs May directly during a bilateral meeting on the margins of the summit. However, the prime minister stuck to a previously repeated position, that it would be triggered "by the end of March".

Speaking to reporters at the end of the summit today, Mr Kenny said there would be a special summit of EU leaders on 6 April, "provided" the British prime minister "moves Article 50 by March 15".

But he said he could not confirm that the prime minister would trigger Article 50 by 15 March.

"I asked the prime minster directly yesterday and she said, 'Well, I did say before the end of March'".

Mr Kenny added: "I suppose Article 50 being triggered will bring some clarity in that regard.

"I would point out that the officials dealing with this in Dublin have been in very close contact with their British counterparts, indeed with Brussels, with Belfast and at home.

"They've done a great deal of background work and we will respond when Article 50 is moved in some greater detail."

Officials have been holding detailed technical discussions on how a post-Brexit border in Ireland might be as "frictionless" as possible, with the use, it is understood, of vehicle licence plate recognition technology.

Asked if Irish, British and EU officials had reached the limit of these technical talks on ways to ensure there would be no harder border, Mr Kenny said: "No, what it means is that we're at the start of the political talks, because politics will lead technology."

"We have a very clear agreement that we will not go back to a hard border, which brought with it sectarian violence and all of that before.

"What the British government have said is that they want as close as possible a relationship with the European Union. We support that. But there are political challenges in there, removing of [Britain from] the single market and the attitude towards the customs union."

EU leaders to mark Treaty of Rome

EU leaders are in Brussels to prepare the groundwork for the 60th anniversary of EU's founding treaty at a celebration in Rome at the end of the month.

The British prime minister has been excluded from the meeting.

Six countries signed the Treaty of Rome 60 years ago.

The signing of the Treaty of Rome in 1957

It created a Common Market and built upon the European Coal and Steel Community which was designed to thwart any possibility of another European War.

Back then the European ideal was very different. The founding fathers dreamed of a United States of Europe, a peace-promoting world power alongside the US and Soviet Russia.

Now 60 years on, the vision is very different.

For the first time ever a member state, in fact the second largest economy in the EU, is leaving. Eurosceptic parties are on the rise, and the future of the transatlantic alliance has been put in doubt by US President Donald Trump.

So, leaders have been looking at what should inspire the celebrations in Rome - noticeably absent is any language about deepening integration or enlarging the EU.

Instead, the emphasis is on completing legislation already there, such as the single and digital market, as well as improving cooperation to protect European citizens against terrorism.

A draft working paper says Europe should keep promoting free trade agreements, an obvious riposte to the Trump administration, and should also strengthen its defence and security footprint.

There is also the idea of a multi-speed Europe, where groups of countries can integrate more deeply at their own pace.

But that is something the Irish Government would prefer to avoid, the feeling being that at such a time, Europe needs to be united.

Last night, Poland was isolated after its prime minister tried to block the re-appointment of Donald Tusk as president of the European Council.

Mr Tusk, a former Polish prime minister, is the man who formally represents all 28 EU leaders. He chairs EU summits and generally tries to broker consensus among the member states.

He has been highly praised during his first two-and-a-half year term, with the Taoiseach a strong supporter.

However, the one country that vehemently rejected his reappointment was his native Poland.

The right wing Law and Justice Party, currently in government in Poland, has nursed simmering rage against its former party political rival, even after Mr Tusk's departure for Brussels.

The party accuses him of being morally responsible for the plane crash which killed the former president of Poland and a large section of the Polish government in 2010.

Two official inquiries have attributed the crash to pilot error.

Last night, Polish Prime Minister Beate Szydło tried to block a second term for Mr Tusk.

The rotating presidency of the EU took the unusual step of forcing a vote, and he was approved by a margin of 27 to one.

Law and Justice Party leader Jaroslaw Kaczynski said the vote proved that the EU was run by Germany and that it would be consigned to history.