UNITED NATIONS -- Recalling the world has just come through a year of discord, disease and disruption, UN Secretary-General Ban Ki-moon on Wednesday said the year 2015 must be a time for global action.

Addressing the reporters in an end-of-year press conference, the UN chief highlighted four imperatives for next year, including securing a climate change agreement, averting escalation of situations in Syria, countering extremism, and adapting UN to a new global landscape.

While hailing the results of the Climate Summit meeting in Lima, Peru, such as agreeing on a draft negotiating text and capitalizing the Green Climate Fund with an initial 10 billion U.S. dollars, Ban said though there is still a great deal of work ahead on finance and other difficult issues, all governments agree they must curb the growth in emissions, which is encouraging.

On Syria, Ban said this year in the country, the dismantling of the chemical weapons program has been of little consolation, and "2015 must be the year in which we end the nightmare in Syria -- and avert the escalation of other worrying situations."

He said regardless of what kind of argument or difference of opinions there may be, the violence must stop, after almost four years of killings.

"As we started the Geneva meeting, then whatever it may be, we need to sit down together, sort of a Geneva II or whatever it may be called," he said. "But the -- unfortunately, the atmosphere has not been created."

On counter-extremism, Ban said we must do more to counter extremism and the rise of far-right political parties that target minorities, migrants and in particular Muslims.

Noting the slaughter on children in Pakistan Tuesday, Ban said "recently, the international community has been troubled by all this spread terrorism and extremism, here and there...We have seen so many such things, in Pakistan, in Afghanistan and Nigeria and Somalia and elsewhere."

The UN is now actively engaging with the countries which are in danger, who are vulnerable to terrorism and extremism and will try to help those member states to strengthen their national capacity, he added.

Ban also pointed to the impacts of conflicts in Syria, South Sudan and Ukraine, as well as to the spread of extremist insurgencies in Nigeria and Iraq, and instability in Afghanistan and the Sahel.

Over the past year, peace operations, diplomacy and humanitarian capacities have been pushed to the limit. More than 100 million people need assistance and more than 50 million people have been driven from their homes -- the most since the Second World War, according to the UN chief.

As for the issue of Israel and Palestine, Ban said the two sides have a responsibility to step back from the brink, ease the current tensions and salvage a two-state solution that is looking ever more remote.

Ban also briefed the crowd about his visit to the most affected countries by the Ebola virus, saying the outbreak of Ebola in West Africa has challenged the international community in unprecedented ways.

"I want to see the response for myself, and show my solidarity with those affected and urge even greater global action," he said. "But now is not the time to ease up on our efforts. As long as there is one case of Ebola, the risk remains. We must do everything we can to get to zero."

The year 2015 marks the 70th anniversary of the United Nations and is also the penultimate year of Ban's tenure until Dec. 31, 2016.

According to the UN chief, a number of key reviews of the United Nations' work will come to fruition in 2015, including panels on peace operations which was launched last month, peace-building review by the General Assembly, and humanitarian financing and implementation of the Security Council's landmark resolution 1325 on women, peace and security.

"These assessments are an opportunity to build on the other reforms we have pursued throughout my tenure," he added.