United Nations chief Ban Ki-moon has recommended that the UN's special mission in Nepal be extended, warning of escalating post-war tension in the Himalayan country. In a report to the UN Security Council, Ban expressed serious concern at Nepal's political stalemate and said the next few months would be crucial for the peace process, which began when a civil war ended in 2006. 'Positions have hardened at the opposing ends of the political spectrum, which has seriously eroded the common middle ground that had, from the outset, defined the peace process and remained its driving strength,' he said. 'There is a growing and worrying risk of the political discourse being dominated by extreme voices and the focus shifting away from the peaceful and democratic path.' The UN Mission in Nepal (UNMIN) was set up in 2007 to support and monitor the peace process, after a 10-year civil war between Maoist rebels and the state. Its mandate is due to expire on January 23. The Nepal government has asked for the political mission to be extended until May 15 and the Security Council will vote on the issue in the coming days. Ban said withdrawing the mission now would be unwise, although he urged Nepal's political parties to agree a timeline that would create an 'unambiguous exit strategy' for the UN. The UN has repeatedly criticised the slow pace of Nepal's peace process, which includes drafting a new constitution by the end of May and integrating thousands of Maoist former fighters into the regular army. More than 16,000 people died in the war between the Maoists and the state, and deep suspicions persist. Thousands of Maoist soldiers remain in UN-monitored camps around the country awaiting integration, but the army opposes such a move, and negotiations to end the stalemate have failed to reach a compromise. There are also fears that the new constitution will not be written on time given major differences among Nepal's political parties including the Maoists. 