The Secretary General of the Department of Public Expenditure and Reform, Robert Watt has said he does not envisage the Lansdowne Road Agreement being revisited.
Mr Watt told a media briefing that "the agreement was the agreement."
Mr Wall said that any money diverted to public sector pay would mean less money for the improvement of services.
He said that Agreement is delivering increases in pay in 2016, 2017 and 2018 and he outlined that a clerical officer would see an average increase of 9%, a garda 8.5%, a nurse between 7.5 and 8% and a teacher 7%.
Mr Watt said that the end of the Agreement in September 2018 would see almost full restoration of pay for the lowest paid public servants, following cuts implemented since 2008.
Mr Watt also denied that were what he called "generalised difficulties" in recruiting to the public service, with 9,800 net staff recruited between January 2014 and December 2015, including over 1,000 nurses, over 1,000 consultants, and over 3,000 teachers.
Mr Watt highlighted that over 25,000 applications were received for 550 gardaí positions in January 2014, following a moratorium on recruitment.
Mr Watt said that while there were particular areas where recruitment was challenging, "across the grades we do not have an issue," he said.
Mr Watt also said that basic starting salary figures for nurses and garda failed to take into account of allowances, premium pay and overtime.
In the case of gardaí, the Department puts the starting salary at €23,750, however Mr Watt said the average salary for a new recruit after a year was €31,000 after allowances and overtime were taken into account.
"I know that agreement lasts until September 2018 but if we can't recruit teachers, and we can't recruit gardaí, or civil servants, or nurses because of the pay then we need to revisit it," he said.
"These are the young people we rely on to stay in the country, these are the young people who are vital to our public services and our front-line provision of those services."
He added: "If the finances are available, and maybe they are, that's where I would put the priority."
Earlier this evening the head of the Workplace Relations Commission, Kieran Mulvey, said the Lansdowne Road Agreement has to be "revisited" if gardaí, teachers or nurses cannot be recruited because of pay.
Speaking on RTÉ’s Clare Byrne Live, Mr Mulvey said the situation regarding gardaí, nurses and teachers at entry-grade level "is a problem that comes back to bite you after a while".
Mr Mulvey said he believed there was such controversy around the issue that it will have to be addressed again in the context of the Agreement.
Meanwhile, addressing the row that occurred between himself and SIPTU President Jack O'Connor in which Mr O'Connor said Mr Mulvey should resign, he called it a "sideshow" to the Luas dispute.
"We've known each other for 25 years. We've never had a disagreement to my knowledge,” said Mr Mulvey.
"We'll sort this out. I don't think we should worry about it. It's a sideshow to the essential issue."
Teachers' Union of Ireland President Gerry Quinn said he is aware of young teachers who have left jobs because of what he said was income poverty.
He said the union has been campaigning on the issue for some time.
Civil Public & Services Union General Secretary Eoin Ronayne said the LRA was the pathway to future change and that agreements are there for a purpose and place in time and if matters evolve then agreements can change to.
He said if the Haddington Road deal could be renegotiated, then the LRA could also be moved onwards.
Garda pay review to go ahead in June
The President of the Garda Representative Association Dermot O'Brien said that gardaí are the only public servants signed up to a review of pay and conditions under the Haddington Road process, and he is optimistic that that it yield a result for his members between now and the end of June.
The review that is being carried out by retired member of the Labour Court Ray McGee and it got under way in February.
The GRA and Association of Garda Sergeants and Inspectors rejected the Lansdowne Road Agreement last year.
He added that the issue of low entrant pay is becoming more real and critical as time goes on.
Earlier today the Department of Public Expenditure and Reform issued a statement saying the LRA terms provided for the "gradual unwinding of the pay reduction measures imposed on public servants at a cost of €844m over three years".
The statement continued: "The Department indicated that this was prudent and sustainable given the current resources available and fiscal restraints on spending.
"In line with commitments given, priority was given in the Agreement to those public servants on lower pay.
"It has been adopted by the Public Services Committee of the ICTU and therefore represents the agreed structure for industrial relations and pay within the public service. It is now underpinned by the FEMPI Act of 2015.
"The Department is obviously not in a position to comment on future Government policy."