United Nations Secretary-General Ban Ki-moon is “disappointed” in Nepal's failure to craft a new constitution before a Sunday deadline.

In a statement Monday, Mr. Ban's spokesperson said the Constituent Assembly came to important agreements on nearly all aspects of the document except state restructuring.

The issue divided lawmakers, with the four main parties trying to agree on whether new states in a federal Nepal would be drawn on the basis of ethnicity. Opponents of the idea said it could fuel more unrest.

The Constituent Assembly began working in 2008 after the abolition of Nepal's centuries-old Hindu monarchy. But after having extended its tenure four times, the Supreme Court rejected any further extensions.

Elections are scheduled for November 22 to choose a new assembly.

Mr. Ban said work on the constitution should resume “without delay,” and that leaders should be willing to “set aside lesser differences” in the interest of the nation.

He also called on all parties to reaffirm their commitment to the spirit of a 2006 peace agreement, which ended a decade-long insurgency by Maoist rebels. The fighting claimed more than 13,000 lives.

Last November, Nepal's main political parties agreed to a deal to integrate thousands of former Maoist fighters into the army, a move seen as bolstering the peace process.

The government placed security forces in the capital, Katmandu, on “high alert” Sunday after demonstrators clashed with police outside the parliament building.