Thirty-one cases of Covid-19 in Ireland were associated with travel last month, the deputy chief medical officer warned.
The Government has warned against non-essential foreign travel and said it risked undoing the progress the country has made in combating the virus.
Chief medical officer Tony Holohan advised residents to cancel foreign holidays to prevent a potential second surge.
Ryanair is operating 40 of its scheduled flights across Europe from Wednesday and the Government is due to release a “green list” of countries deemed safe to travel to later this month.
Dr Ronan Glynn, deputy chief medical officer, said: “In June, a total of 31 cases of Covid-19 in Ireland were associated with travel.
“The balance of keeping the disease suppressed in Ireland will continue to be challenging as society and business reopens.”
Dr Holohan said the World Health Organisation (WHO) had warned that the global pandemic is accelerating.
He added: “In the past week, over 160,000 cases have been reported each day.”
Meanwhile, recently-published public health advice said older students at primary school and post primaries should maintain at least one metre physical distance from each other during class times when they reopen in September.
Education minister Norma Foley said: “This interim advice provides a platform for deep engagement with all of the school stakeholders over the coming weeks: principals, teachers and all school staff, students, parents and education partners.”
The National Public Health Emergency Team will meet again on Thursday as it continues to monitor the spread of Covid-19 nationally and internationally, and review Ireland’s response and preparedness to the disease.
Three more people have died with the disease, the team said on Wednesday, bringing the total toll to 1,738.
The authorities were notified of another six confirmed cases, making a total of 25,477.
Senior civil servant Liz Canavan of the Department of the Taoiseach said on Wednesday that additional movement due to the lifting of restrictions means the risk of virus spreading becomes greater if people do not act responsibly.
She said: “It is important to remember the early days of this pandemic and that early cases were associated with international travel.
“We realise how infectious Covid-19 is and the very real possibility that a person may not show any symptoms. The risk now is that imported cases will spread infection before we can identify the chain of transmission.”
It's good to be back👋— Ryanair (@Ryanair) July 1, 2020
This morning we restarted our schedules with 1000 daily flights across Europe 🛫 pic.twitter.com/JZ8DRjDzLG
Ms Canavan said the situation regarding imported cases is “volatile” but the Government plans on giving an update about travel in the coming weeks.
“We understand that the issue of foreign travel is causing great uncertainty and worry. Some people have holidays booked and don’t know what to do – we are acutely aware of this and ask you to bear with us.”
Earlier, an infectious disease specialist said it is safe to travel abroad as long as coronavirus protocols are adhered to.
Jack Lambert, of the Mater and Rotunda hospitals, told RTE radio: “If we do the hand-washing, social distancing and wear a face mask then yes, it is safe to travel.”