UNITED NATIONS - The United Nations General Assembly (UNGA) on Tuesday opened its 76th session, with the UNGA president and the UN chief imploring member states to embrace hope and strengthen unity after a challenging year of climate disasters, conflict, and COVID-19.

"It has been a tragic and challenging year, but this is a new session," said President of the 76th UNGA session Abdulla Shahid. "We can fall back on the comfort and predictability of systems and procedures, of the United Nations machinery that fills our days, or we can choose to push forward and turn the page. We can choose to write a new chapter."

"Let us choose the latter; let us dare to dream and let us dare to hope, to embrace the presidency of hope," said Shahid.

Highlighting the challenges ahead, he said that hundreds of millions have fallen ill, millions died, and billions suffered from the pandemic, with news arriving daily to ignite the world's collective anxiety about climate change, disasters, conflict and instability.

"The narrative must change, and we must be initiator for that change; the General Assembly must play a part of this," he said, emphasizing that the United Nations is as relevant today as it was 76 years ago.

Declaring that he embraced hope as the theme of his presidency, he said, "While the pandemic unleashed an unprecedented crisis, we have witnessed incredible acts of kindness and compassion, acts that reaffirmed our common humanity and collective strength as 'nations united.' This is the narrative we must tell."

Listing five rays of hope that will shape the 76th session's agenda, he said vaccinating the world is the top priority.

"By any measure, this has been the most challenging period facing the world since the Second World War," said UN Secretary-General Antonio Guterres in his remarks delivered at the closing of the 75th UNGA, which was followed immediately by the opening of the 76th session.

However, the international community can overcome all these challenges "by working as one," the secretary-general noted.

On COVID-19, the top UN official said that the pandemic has deepened inequalities, decimated economies at the global, national and household levels, plunged millions into extreme poverty, shattered support systems and unraveled decades of hard-won development progress.

"This devastation has played out against the backdrop of ferocious conflicts and natural disasters that are putting millions of lives in jeopardy every day," said Guterres, adding that a climate emergency is "literally setting our planet on fire."

Addressing the opening of the 76th UNGA session, the UN chief said that "it's time to focus on fighting humanity's common enemy: the pandemic."

"We need to speed up our response to COVID-19, with vaccines, treatment and equipment for all -- not only those with the most," the secretary-general added.

"We need countries to commit and live up to bold climate targets at COP26 in Glasgow," the top UN official added. "The war on our planet must end."

Noting that "we meet at a moment of great challenge and division," the secretary-general said that these challenges facing the world "are worsened by the divisions scarring our world," divisions "between the rich and (the) poor, between those who take basic services for granted -- nutrition, running water, accessible health care -- and those for whom these essentials remain a distant dream"; divisions between those with a seat in a classroom and skills to build a better future and those who lost such opportunities because of poverty or their gender, and "divisions between those able to access life-saving COVID-19 vaccines and those who cannot."

"These challenges and divisions are not a force of nature," he said, "They are man-made."

The divisions "are made by economic systems stacked against the poorest and most vulnerable; by unchecked greed that is destroying our planet; by the lingering scars of colonialism that have never fully healed and by thirst for political and ideological dominance that fuels social unrest, mistrust, terrorism and armed conflicts," the UN chief continued.

These challenges and divisions can be corrected "if we unite behind our work here in this chamber and gather around the spirit of multilateralism," added the secretary-general.

President of the 75th UNGA session Volkan Bozkir called for redoubling efforts to implement the Sustainable Development Goals (SDGs), while expressing concern that the 2030 deadline might be missed.

Noting that the SDGs represent a blueprint for peace and prosperity, for people and the planet, for now and into the future, and implementing these goals will help protect the international community against future catastrophes, he warned that "with the trajectory we are on, we are going to miss the 2030 deadline."

"This Assembly and you -- the member states who make up the United Nations -- must redouble efforts to implement the SDGs," Bozkir said at the closing of the 75th UNGA session.

On multilateralism, the veteran Turkish diplomat said, "We must strengthen and unite behind the multilateral system."

"Our world is increasingly globalized, interconnected and interdependent. As such, nationalistic solutions will not resolve our challenges," he stressed.