The proposal would also see an hourly frequency between the two cities
Iarnród Éireann and Translink have launched a new plan for an hourly service between Dublin and Belfast.
The 'Better Connecting Dublin and Belfast' strategy sets out a road map of how both companies jointly plan to further enhance the service.
The plan is a three-staged approach - starting with the introduction of a new fleet to allow for an hourly frequency between the two cities.
With additional investment in infrastructure and line improvements, it sets out to reduce the average journey time to less than two hours.
From there, the longer-term hope is to introduce electrification on the line which would achieve further frequency improvements, and a journey time of potentially 90 minutes or less.
The plan was launched at an event as part of 'Bus + Train Week 2018' at the Europa Hotel in Belfast.
Speaking at the event, chairman of Irish Rail Frank Allen said: "This is a strategy founded in partnership.
"The partnership between both railways, within which generations have worked together from platform to boardroom to build the joint service we offer our customers today.
"Our joint strategy builds upon that legacy to continue to enhance the role we can play for the customers and communities we serve.
"The partnership with our stakeholders in business, tourism, central and local government and other major sectors is reflected in this strategy also.
"Our stakeholders have engaged with us as we have developed this strategy, and we value their continued partnership as we seek to support each other in what our rail services achieve for our economy and society in the years ahead.
"The next steps are to secure funding to take this project forward and Translink and Iarnród Éireann are keen that approval is granted to start procurement of a new Enterprise fleet and to fund a project to undertake a detailed Technical and Feasibility study to further assess the journey time improvement options", he added.
Chairman of Translink Frank Hewitt said: "Developing the Cross-Border Enterprise Rail Service will be essential to further strengthening economic links and is key to building competitiveness and increasing close communication links between our two capital cities.
"The plan launched today aligns with both Programmes for Government to support the growth of public transport while also delivering social and environmental benefits by decongesting roads, promoting all-Ireland Tourism and reducing carbon emissions."
Last year almost one million passenger journeys were made on the route.
There are around 3.3 million people living within a 40-mile commute from the Belfast-Dublin Corridor.
This is expected to grow to four million by 2030.