On 12 February 2015, the DPR and LPR leaders, Alexander Zakharchenko and Igor Plotnitsky, signed the Minsk II agreement. In the Minsk agreement it is agreed to introduce amendments to the Ukrainian constitution "the key element of which is decentralisation" and the holding of elections "On temporary Order of Local Self-Governance in Particular Districts of Donetsk and Luhansk Oblasts, based in the line set up by the Minsk Memorandum as of 19 September 2014"; in return rebel held territory would be reintegrated into Ukraine. Representatives of the DPR and LPR continue to forward their proposals concerning Minsk II to the Trilateral Contact Group on Ukraine. In an effort to stabilize the ceasefire in the region, particularly the disputed and strategically important town of Debaltseve, in February 2015 Ukrainian President Petro Poroshenko called for a UN-led peacekeeping operation to monitor the compliance with the agreement achieved during the Minsk peace talks.