One year ago today, the Foreign Secretary, William Hague, was in Juba to witness the birth of a new nation. This was a historic moment, which marked the culmination of a peace process that had put an end to Africa's longest-running civil war.
As William Hague formally opened the British Embassy in Juba, he promised the people of South Sudan that the UK would support and assist their efforts to build a successful and peaceful nation. Together with my colleagues, I have worked hard in the last year to ensure we have kept that promise.
As the first country to accredit an ambassador to the new country, and with a substantial development and humanitarian programme addressing the pressing needs of the South Sudanese people, the UK has led the way in fulfilling the commitments made by the international community on 9 July 2011.
But while the anniversary offers a chance to look back and to take note of the progress that has been made in the last year, it is more important to look forward - one year on, the challenges are more evident than ever.
The last 12 months have presented a test of political leadership to the governments of Sudan and South Sudan; it is a test neither has passed. Differences between Sudan and South Sudan not resolved at independence, brought the two countries to the brink of war in April. The increasingly precarious economic situation of both countries was worsened by a break-down in trust that led to the shutting of South Sudan's oil wells. Worryingly, we see growing numbers dependent on humanitarian assistance from international donors.
The international community stands ready to help, but the responsibility to make change and the power to effect it sits with Governments of South Sudan and Sudan. These governments are now faced with the opportunity to make changes for the better. They must seize it.
South Sudan's government needs to complete the transition from armed liberation movement, and focus on the establishment of a pluralistic government based on the democratic rights of its people. It needs to end its support to armed rebel movements inside Sudan, and to work with the UN to ensure internal security and an end to inter-communal violence in South Sudan.
The Sudanese government must break with the failed policies of the past, with power held by a political elite that cracks down on freedom of expression and detains political activists. It must end the unnecessary and destructive wars against its own citizens in Southern Kordofan and Blue Nile. And it must provide the resources necessary to ensure that the present Darfur Peace Agreement has a real chance of improving lives in that region. I have followed closely the demonstrations in Khartoum and other Sudanese cities in the past few weeks. The Government of Sudan must now deliver the democratic reforms that these protests have demanded.
The two governments must also work together. It is vital they agree a just settlement. This will allow South Sudan to make best use of its oil revenues, and to invest in the infrastructure and basic services the new country needs. It will also set Sudan on the path to reintegration within international political and economic systems. Agreeing a settled and secure border would facilitate trade, and allow peoples of both countries to maintain family, cultural and religious links.
I have seen at first hand the suffering that conflict has caused in Sudan and South Sudan, and the enormous humanitarian and development needs that must be met. But I have also been encouraged by the great potential in two countries rich in agricultural land, mineral resources, and blessed with diverse peoples. The anniversary of South Sudan's independence offers a real opportunity for the leaders of South Sudan and Sudan to reflect on the challenges and choices that lie ahead of them. Provided they make the right choices, I will ensure the UK is there to help them every step of the way.