More than 117,000 confirmed cases of COVID-19 among children were reported in the United States last week, representing a 10% increase in cases between Jan. 21 and Feb. 4, according to a report released Monday by the American Academy of Pediatrics and the Children's Hospital Association.

The report, which compiles state-by-state data on infections among kids, found that 2.9 million children have tested positive for COVID-19 nationwide since the start of the pandemic. In total, children represent 12.9% of all cases in U.S. states that report COVID-19 data by age.

ABC News' Arielle Mitropoulos contributed to this report.

Facebook announced Monday a global campaign to promote authoritative COVID-19 sources and push back on disinformation.

The effort will including helping people find out where and when to get vaccinated, expanding the social media company's efforts to remove false COVID-19 information from Facebook and Instagram, and giving $120 million in advertising credits to health ministries, NGOs and UN agencies.

Facebook also said it would provide data for education to help build trust in COVID-19 vaccines, as well as to inform vaccine delivery efforts.

ABC News' Mary Kathryn Burke contributed to this report.

Ten percent of Americans, or 31.6 million people, have received one or more doses of the COVID-19 vaccine, according to a U.S. Department of Health and Human Services planning document obtained by ABC News.

Three percent of the population, or 9.1 million people, have gotten both shots of the two-dose vaccine, according to the document.

U.S. President Joe Biden has pledged to get 100 million shots into Americans' arms during the first 100 days of his presidency. Since his Jan. 20 inauguration, 24.6 million doses have been administered.

ABC News' Josh Margolin and Brian Hartman contributed to this report.

U.S. Rep. Ron Wright, R-Texas, died Sunday after contracting COVID-19 last month, his office confirmed in a statement Monday.

Wright, who had lung cancer, was diagnosed with the disease on Jan. 21 and admitted to Baylor Hospital in Dallas. He was 67.

"Over the past few years, Congressman Wright had kept a rigorous work schedule on the floor of the U.S. House of Representatives and at home in Texas’ Congressional District 6 while being treated for cancer," his office said.

Wright is the second American lawmaker to die after testing positive for COVID-19. Luke Letlow, Louisiana's incoming Republican congressman, died at age 41 in late December, just days before he was due to be sworn in.

ABC News' Mariam Khan contributed to this report.

An international team of World Health Organization experts investigating the origins of the coronavirus pandemic said Tuesday it's "extremely unlikely" that the virus was leaked from a laboratory in the Chinese city of Wuhan.

The Wuhan Institute of Virology, which is affiliated with the government-run Chinese Academy of Sciences, has collected extensive virus samples, sparking speculations that it may have caused the original outbreak by leaking the novel coronavirus into the surrounding community. The institute has strongly rejected that possibility.

"The findings suggest that the laboratory incident hypothesis is extremely unlikely to explain the introduction of the virus into the human population," WHO food safety and animal diseases expert Peter Ben Embarek said at a joint press conference with Chinese counterparts on Tuesday. "Therefore, [it] is not in the hypotheses that we will suggest for future studies."

The WHO team, which includes experts from 10 countries, is considering several possible scenarios for how the disease was transmitted to humans, leading to a pandemic that has claimed the lives of more than 2.3 million people worldwide. Embarek said it's more likely that the virus jumped to humans from an animal.

"Our initial findings suggest that the introduction through an intermediary host species is the most likely pathway and one that will require more studies and more specific targeted research," he said.

Transmission through the trade of frozen products was also likely, Embarek added.

As part of their investigation, the WHO team has visited key locations in Wuhan, where the first cases of COVID-19 were detected in December 2019.

A cluster of initial cases has been linked to a now-closed wet market in Wuhan. But Liang Wannian, the lead Chinese envoy who is working on the probe, said the market may not be the first location of the outbreak since transmission was also happening in other areas of the city at the time.

A review of mortality data, antibody tests of blood in blood banks in Wuhan and genome sequences showed there was "no indication of the transmission of the Sars-Cov-2 in the population" prior to December 2019, according to Liang.

There was also no evidence of "large outbreaks" in Wuhan or elsewhere before December 2019, according to Embarek.

ABC News' Karson Yiu contributed to this report.