The EU has pledged more than 23m euros (£19.5m) to create almost 80 kms (50 miles) of new greenway linking towns and cities on either side of the Irish border.
Funding will go to new projects connecting Newry with Carlingford and Londonderry and Strabane with Donegal.
The second phase of the Ulster Canal Greenway will also benefit.
It is hoped the projects will cut car journeys and create sustainable travel routes for cyclists and pedestrians.
Gina McIntyre of the Special EU Programmes Body said teach of the projects would "substantially increase the quality and quantity of greenway offering on both sides of the border".
The Department for Infrastructure in Northern Ireland and Ireland's Department of Transport will match fund the EU monies.
Northern Ireland's Infrastructure Minister Chris Hazzard said the EU funding "demonstrates commitment to further develop sustainable transport options here".
"The benefits of developing greenways go well beyond transport. The health, economic, environmental and social impacts help enhance the quality of life for users".
Mr Hazzard said the new routes would complement Northern Ireland's five existing greenways that span around 600 miles.
The North West greenway - three separate routes totalling 46.5 kms linking Derry to Buncrana in County Donegal, Derry to the Donegal village of Muff, and Strabane to Lifford - is the single biggest recipient of EU funding. It will receive 14.9m euros.
The Carlingford Lough Greenway - a 10-km route linking Newry to Carlingford - has been offered 3.5m euros, while the second phase of the Ulster Canal Greenway is to receive 4.9m euros.
It follows the route of the old Ulster Canal from Smithborough in county Monaghan to Armagh.
Minister for Transport, Tourism and Sport Shane Ross said the greenways "further enhance the level of cross-border co-operation between jurisdictions".
"The potential for these routes to be used by commuters travelling to and from work each day offers an opportunity to reduce dependence on the private car and help reduce carbon emissions.
"They also offer excellent potential to attract visitors to the areas with positive impacts on local economies."
It is hoped the new greenways will allow cross border cycling and walking to increase by 10% by 2023.