PARIS (AFP) - World leaders on Saturday hailed the birth of the world's newest nation, the Republic of South Sudan, as an historic event bringing to a close 50 years of conflict in northeastern Africa. US President Barack Obama led official recognition of the country, calling it "another step forward in Africa's long journey toward opportunity, democracy and justice." "I am proud to declare that the US formally recognises the Republic of South Sudan as a sovereign and independent state upon this day," Obama said in a statement. UN chief Ban Ki-moon, speaking at the official ceremony in Juba, said it was an important day for the UN. "Today we open a new chapter when the people of South Sudan claim their freedom and dignity that is their birthright," he said. Messages of congratulation flooded in from nations around the world including Canada, Egypt, Ethiopia, Kenya, Libya and Turkey. "Today a new country is rising in Africa. I congratulate South Sudan on its independence and wish its people a prosperous and peaceful future," said EU president Herman Van Rompuy in a Twitter message. Amid tears of joy in Juba, South Sudan's parliament speaker on Saturday proclaimed his state's independence, splitting in two what had been Africa's largest nation. South Africa's President Jacob Zuma said Africans from the Cape to Cairo were proud of South Sudan's independence, after decades of conflict between the southern rebels and successive Khartoum governments that left the region in ruins and claimed millions of lives. "We have always aspired to witness the dawn of peace, security and stability prevailing in the whole of the Sudan. That dream is coming to fruition," said Zuma, adding however that "change always brings uncertainty and discomfort." Germany's Chancellor Angela Merkel welcomed the move as "a day of joy and great hope for the people" of the world's new country. Offering help to the new nation, she said it was now important "to back S. Sudan on the road to stability that will bring people peace, security and economic development." In France, President Nicolas Sarkozy said the independence declaration was the fulfillment of an exceptional process, initiated by a peace accord in 2005, that all the international community supported and that "the North and South (of Sudan) brought courageously to completion." British PM David Cameron said an ambassador to Juba had already arrived to take up his post. "This is an historic day, for South Sudan and the whole of Africa," he said, adding that Britain was proud to be "among the first to recognise South Sudanese independence". Russian President Dmitry Medvedev sent a telegram of congratulation to his South Sudanese counterpart and also expressed interest in the vast oil reserves in South Sudan. China's special envoy extended President Hu Jintao's "warmest congratulations" to the "young Republic" of South Sudan, while noting the ongoing negotiations between north and south. He said Beijing, Sudan's main trading partner and the largest investor in its key oil industry, hoped the two sides could be "good neighbours, partners and brothers forever."