New UN envoy to Libya Martin Kobler on Sunday stressed the need for Libya's rival political camps to quickly sign onto a proposed political agreement following months of negotiations. The proposed agreement is meant to cover a one-year transitional phase, until a referendum on a new constitution and legislative elections can be held. Kobler made the remarks at a Sunday press conference held at the headquarters of Libya's Tripoli-based General National Congress (GNC) after holding a closed-door meeting with members of the GNC's negotiating team. Kobler arrived in Tripoli on Sunday for his first-ever visit after visiting the city of Tobruk one day earlier, where he met with the vice-president of the Tobruk-based House of Representatives, the GNC's political rival. At Sunday's press conference, the UN envoy asserted the need to "move quickly towards the signing of a political agreement that will create strong and legitimate state institutions and enjoy the support of the Libyan people and the international community". Kobler also voiced concern about the potential spread of the ISIS militant group and mounting insecurity in war-torn Libya. "The war on terror [in Libya] must be led by unified and legitimate Libyan institutions with the help of the international community," he said. Awad al-Sadiq, head of the GNC's negotiating team, for his part, stressed the importance of dialogue to resolve the country's political crisis and praised international efforts to resolve the ongoing deadlock. Al-Sadiq went on to note that members of his team had told the new envoy of their surprise over recent leaked emails concerning Kobler's predecessor, Bernardino Leon, which, they said, could have derailed the ongoing talks. Last week, The Guardian newspaper published leaked emails between Leon and United Arab Emirates Foreign Minister Abdullah bin Zayed. The leaked mails appeared to show Leon's bias in favor of the Tobruk-based House of Representatives, while also revealing the fact that Leon -- while serving as UN envoy to Libya -- had been receiving a hefty monthly salary from Abu Dhabi's International Academy for Diplomacy. According to al-Sadiq, GNC officials had asked the UN for "clarification" regarding the information revealed by the leaks but had yet to receive a response from the world body. The proposed UN-backed agreement for Libya was initialed by both sides earlier this year in the Moroccan city of Skhirat. The deal calls for the House of Representatives to serve as Libya's legislative authority, a State Council to serve in an advisory capacity, and a council for the head of government, to be composed of representatives from all the country's political parties. The terms of the agreement are meant to last for an extendable one-year period.