Restrictions on travellers entering Ireland are likely to remain in place until the middle of next year, the Irish premier has said.

Micheal Martin said the need for people to self-isolate on their arrival in the Republic would most likely continue until well into next year and could be dependent on a “vaccine or better therapeutics”.

People who travel to Ireland from Britain and other countries, with the exception of Cyprus, Finland, Latvia and Liechtenstein, must agree to self-isolate for two weeks on their arrival.

The Taoiseach recognised the need to quarantine was “problematic”, especially for members of the Irish community living in Britain, but he said the measures were necessary to limit the spread of Covid-19.

“It is very difficult,” Mr Martin said.

“It is really stressful and difficult for families who have not met their loved ones for quite some time because of Covid-19.

“The challenge I think is going to continue for some time. If I’m honest I believe we have to look to the middle of next year to see if any respite is on the way in the form of a vaccine or better therapeutics and that we learn to live with and deal with the virus more effectively.”

Mr Martin made the comments during an interview with the i newspaper broadcast at the Liberal Democrats’ online party conference on Monday.

Asked whether a vaccine or therapeutics would be the only way of reducing the current restrictions on travel between the UK and Ireland, Mr Martin said Irish Foreign Affairs Minister Simon Coveney and Cabinet Office Minister Michael Gove were working together to see if the Governments could provide mechanisms and better supports to people travelling within the Common Travel Area.

“Again it’s problematic,” Mr Martin said.

“The public health personnel are not convinced yet about testing at airports.”

He added: “Caution is still the order of the day.”

The Taoiseach told the conference that he was “not optimistic” that the UK would strike a post-Brexit trade deal with the European Union.

He said the UK Government’s controversial Internal Market Bill had “eroded trust” between the two sides and Europe was no longer confident that Britain’s word can be relied upon.

“The Internal Market Bill has eroded trust,” Mr Martin said.

“It has damaged, you know, the credibility of agreements that have been entered into, namely the Withdrawal Agreement and the Northern Ireland protocol.”

Mr Martin said the Irish Government was operating on the basis there would be a no-deal Brexit because of a lack of optimism about a trade deal being struck.

“I’m not that optimistic, if I’m honest. The (Irish) Government is preparing its Budget in three weeks’ time on the basis that there will be a no-deal Brexit,” he added.

“That’s the basis upon which we’re preparing our Budget and we’re warning and alerting businesses to that terrible reality.”

But the Taoiseach said there was “still potential” for a deal to be struck.

He said that the Irish Government was “very keen” to ensure that ultimately there would be a “sensible agreement” made between the UK and the European Union.

“A deal is the sane and sensible thing to do,” Mr Martin said.

But he warned: “It will take serious engagement and time is running out.”

The ninth round of trade deal negotiations between the UK and EU will begin on Tuesday in Brussels.

There are fewer than 100 days until the transition period, in which the UK remains in the single market and continues to follow EU law, ends on December 31.