In addressing the challenges of a global pandemic, the United Nations' top official quoted Jean Monnet: "This is not a time for blind optimism or paralyzing pessimism. Now is the time to be determined. Determined to defeat COVID-19 and to emerge from the crisis by building a better world for all."

Speaking during a virtual news conference on the impact of COVID-19 on Thursday, UN Secretary-General Antonio Guterres added that, "Our voice has been clear, calling for solidarity, unity and hope."

In a Q&A session, Guterres was asked about the effect of a growing war of words between the US and China is having on international cooperation against the novel coronavirus pandemic.

In an interview Wednesday, US President Donald Trump told Reuters that he believes China's handling of the outbreak is proof that Beijing "will do anything they can" to make him lose in his re-election bid in November.

Guterres said it is clear that the US and China are two highly important elements in the international community "both from the economic dimension, from the political dimension, from the military dimension".

"These are two absolutely vital countries," he said.

"The contribution of China and the United States, both to fight COVID-19 but to all other aspects in the development of international relations, is, in my opinion, absolutely essential, and I hope that it will become possible in the future," he said.

Guterres said that the UN has mobilized fully to save lives, stave off famine, ease the pain and plan for recovery.

The organization set out a $2 billion Global Humanitarian Response Plan for the most vulnerable populations, including refugees and internally displaced persons. "Donors have generously pledged $1 billion. The plan must be fully funded," he said.

Along with the World Health Organization, the UN also participated in the launch of the ACT Accelerator, a global collaboration to speed the development, production and equitable access to new COVID-19 diagnostics, therapeutics and vaccines.

"These must be available to everyone, everywhere, and they must be affordable as a quintessential global public good," said Guterres calling on donors to help kick-start the effort with generous contributions at Monday's pledging summit in Brussels.

The secretary-general once again appealed for compassion and mutual respect in response to coronavirus-related stigma and hate speech.

Guterres highlighted efforts to achieve a global cease-fire, which depend on strong political backing.

He said the cease-fire call has resonated widely, with endorsements from 114 governments, diverse regional organizations, religious leaders and more than 200 civil society groups spanning all regions. Among those were 16 armed groups.

"But we know that mistrust remains high, and that it is difficult to move to implementation," Guterres said.

He said he hopes the Security Council will be able to find unity and adopt decisions that can help make the cease-fires meaningful and real.

Guterres also emphasized that people are facing "the most dire economic plight".

The UN's International Labor Organization reported this week that the global workforce will be hit with the equivalent of the loss of more than 300 million jobs.

Poverty could rise by 500 million people — the first increase in three decades, Guterres said.

He said developing countries will need massive and urgent support.

The International Monetary Fund has already approved $12.3 billion in emergency financing to a first group of 36 developing countries of the more than 100 that requested it.