Green Party leader and Minister for the Environment Eamon Ryan said he is "looking forward" to travelling to COP26, after a follow-up test indicated he does not have Covid-19.
Last night it was announced that Mr Ryan had tested positive for Covid-19 and had cancelled his plans to travel to the climate conference in Glasgow.
However, in a statement this afternoon, the minister's department said that Mr Ryan had received notification from the Health Service Executive that a second test was recommended.
The result of this test showed that Covid-19 was not detected.
The department said: "The public health advice in this instance is that the case is de-notified, close contacts are informed and the person can continue about their business. Minister Ryan now plans to travel to Glasgow for COP26 tomorrow."
Mr Ryan, in a post on Twitter, said he was "looking forward" to bringing Ireland's Climate Action Plan to COP26 this week.
It added: "Minister Ryan has not been symptomatic at any point. He underwent the initial test as a precautionary measure as recommended by the organisers of COP26.
"On receipt of the initial result he followed all HSE protocols, including self-isolation and informing close contacts.
"Minister Ryan has updated the Taoiseach, Tánaiste and the Secretary to the Government with this information."
The Health Service Executive has said that repeat Covid tests may be recommended for individuals in certain instances.
This takes in to account a number of factors, such as the lab result itself including viral targets detected, the reason for the test and the condition of the person having the test performed.
It is typically based on a discussion between the testing laboratory and the person requesting the test, the HSE said in a statement.
"In these cases a repeat test may be scheduled through the HSE Testing and Trace programme and a review of the results will inform the public health guidance," it said.
Minister Ryan, speaking to youth website spunout.ie, said one of Ireland's priorities at COP26 is to help provide climate finance and resources to poorer countries.
He said Ireland emits the equivalent in emissions to 400 million of the poorest people on the planet. "They are the ones who will be first and worst affected by climate change."
Mr Ryan said that "what we have to do in this decade is beyond compare - to halve emissions ... I think we can do it."
The minister said one of the biggest challenges would be public-buy-in. "It's not without difficulty."
Meanwhile Sinn Féin TD, Matt Carthy, has called for clarity on why Minister Ryan's first Covid-19 test result was queried.
In a tweet, he said: "This smacks of another example of the rules being changed to suit ministers."
Mr Carthy said he was glad the second test indicated Mr Ryan is Covid negative "but if there is to be public confidence in the testing regime then the full details of why his first test was questioned need to be clarified".
