Rent pressure zones are to be extended until the end of 2021.
Cabinet today approved an extension to the caps on how much rents can be increased by.
There will be changes to which areas outside of Dublin qualify for rent pressure zone status.
The 4% cap was due to expire at the end of this year.
Simon Coveney told the Dáil changes outside the capital were necessary, "essentially to separate Dublin from the rest of the country because rents are much higher in Dublin".
He added: "The qualification criteria of having to be above the national average needs to change for outside of Dublin."
The Tánaiste said that Housing Minister Eoghan Murphy will provide more details of the changes in the next few days.
Figures released last week showed that annually national rent increased by 6.9% to €1,134 in quarter 4 2018, while the average Dublin rent in the same period was €1,650.
'Rent has continued to surge'
Green Party deputy leader Catherine Martin welcomed the announcement of the extension to the rent pressure zones - but said there are still concerns over them.
She explained: "We have seen that even where RPZs exist, rent has continued to surge. This is due mostly to a lack of enforcement – either on rogue landlords who are increasing rent beyond the cap on existing tenants or by landlords who increase the rents above the cap where there has been a change of tenancy.
"If Government are serious about curbing the growth of rents, then they need to crackdown on these issues.”
According to the Residential Tenancies Board, rent pressure zones - introduced in 2016 - were created in a bid to "moderate the rise in rents in the parts of the country where rents are highest and rising and where households have greatest difficulties in finding accommodation they can afford".
Initially implemented in Dublin and Cork, they've since been extended to encompass more areas - including parts of Galway, Kildare, Meath and Wicklow.
Last week, Navan in County Meath and Limerick City East became the first areas to receive the designation in 18 months.
