RCN Chief Executive and General Secretary Janet Davies made the comments following the publication of a report from the National Audit Office (NAO) criticising the pace and effectiveness of integration efforts so far.
The NAO report said that plans to integrate heath and social care in England by 2020 were at 'significant risk,' as while joint working had improved, pressurised finances and increased care demand was stopping integration from achieving its full potential.
Government integration efforts have been taking place through the Better Care Fund, which pooled an NHS and local government budget of £5.3bn to encourage joined-up working.
Yet the NAO's report says the fund has failed to deliver value for money, improved outcomes, reduced hospital activity and the required savings.
In the wake of this report, Davies has implored the government to clarify the future of its integration policy.
She said: "The RCN supports integrating health and care services, but, as this report identifies, this aim has been buried under a slew of poorly designed integration initiatives in England.
"The need for better co-ordination between health and care services is clear - increasing numbers of people are unable to access social care, and have no option but to fall back on the NHS.
"We would welcome the strong regional and national co-ordination proposed by the NAO, that would bring the Better Care Fund and sustainability and transformation plans closer together.
"But the 2020 deadline is looming - ultimately, a decision must be made whether to extend it or provide more co-ordination, clarity and funding."