In September, world leaders will descend on New York to set goals for creating a more sustainable world, free of extreme poverty by 2030. The 17 proposed Sustainable Development Goals (SDGs) will replace the earlier Millennium Development Goals (MDGs), but unlike their predecessors, these goals will be universal. They will apply to all countries and can only be achieved if all countries act – not just “developing” ones.

But this larger, more ambitious set of goals poses a challenge: How do we make sure that all of those responsible follow through on September’s good intentions? In a voluntary agenda, how do we inject accountability? As the United Nations High Level Political Forum, the body that will review progress on the agenda, wraps up its meetings this week, now is the perfect time to ask these questions.

It may be tempting to write off accountability as impossible without a legally binding agreement. While true that the SDGs by themselves will not have the force of law, it is still possible to clearly assign responsibility, making sure all governments, businesses and other stakeholders have clear objectives and performance standards, as well as answerability, ensuring all actors inform and justify their actions to those affected. Setting out what governments and other stakeholders are responsible for and requiring that they answer for their actions publicly is critical. These are important elements of an accountability framework. All stakeholders should develop clear plans for what they will do to achieve the SDGs, and enable their own citizens to track their progress.

At the same time, no country, rich or poor, will be able to reach the goals in isolation. We live in a globalized economy facing global-scale environmental challenges. Domestic policies in the areas of trade, agriculture, energy, infrastructure, climate change and economic growth (to name just a few) can impact sustainability, poverty and growth elsewhere, both for better or worse. Countries will need to identify these spillovers and externalities and work together to address them, particularly for global public goods like climate change, or freshwater scarcity. Only by the combination of its own and other countries’ actions will any one country fully achieve the SDGs.

At the same time, national governments are no longer the only players. Cities generate 80 percent of global GDP and 70 percent of carbon emissions , putting them at the heart of the action for sustainable development. Similarly, the long reach of global supply chains give the private sector huge potential to lead or lag on environmental sustainability and labor conditions across the globe. And civil society is a vital component of the social pact between governments and citizens – and often uniquely able to evaluate a government’s progress. All three—cities or local governments, the private sector and civil society—will have a role in making progress on SDGs through their own actions, by forming multistakeholder partnerships, and in pushing national governments and each other to lead. And of course, in holding them to account for their commitments.

The word “accountability” has long been a taboo in the SDG negotiations, but we know that making strides against the twin challenges of poverty and environmental degradation will be nearly impossible without ways to not only measure progress, but also delineate clear responsibility for making progress. Speaking in 2010, UN Secretary-General Ban ki-Moon explained the lack of improvement against the MDGs as: “… not because the goals are unreachable, or because time is too short. We are off course because of unmet commitments, inadequate resources and a lack of focus and accountability.”

This September, we will set a transformational global agenda that will no doubt inspire and motivate. But the warm glow will not be enough to carry us through to 2030. The SDGs must be supported by a web of partnerships that spell out who does what, and that can be transparently monitored and assessed. As countries finalize the SDGs over the coming weeks and months, they must not shy away from making accountability a reality.