Children in Ukraine "are in grave danger, especially from the threat of explosive weapons," international humanitarian group Save the Children warned Wednesday.

"Children injured in conflict zones are at even greater risk than adults due to their specific vulnerabilities and treatment needs for blast wounds," Save the Children said in a statement. "Younger children injured in blasts are particularly at risk of death compared to adults and need to be treated differently."

At least 14 children have been killed in Ukraine since Russia launched its invasion on Feb. 24, according to the United Nations.

Save the Children, which has been delivering essential humanitarian aid to children and their families in Ukraine since 2014, called for an immediate end to violence amid fears that many more lives are at risk as Russia's military operation intensifies in major cities and satellite images purportedly show a miles-long convoy of Russian forces closing in on the Ukrainian capital, Kyiv.

U.S. Vice President Kamala Harris stopped short of calling for Russian President Vladimir Putin's ouster on Wednesday while urging for an end to the invasion of Ukraine.

"What we want is that the Ukrainian people will be free and that they will be safe. But we are now at a place where obviously Russia has yet again invaded Ukraine and we must stand in solidarity with our allies and make sure there are severe and swift consequences which is what we've been doing," Harris told ABC News' George Stephanopoulos in an interview on "Good Morning America".

When asked whether there is anything more the United States and its allies could be doing, Harris argued that the actions taken thus far have already had an effect.

"We are seeing the impact of the work that we have done. We are seeing the ruble in a free fall. We are seeing the stock market in Russia has essentially closed. What we have seen is that the credit rating of Russia is now junk," she said. "So, what we know is that we're having an impact and we're taking it quite seriously."

6:17

VP Kamala Harris hails President Biden's plans for American families

Harris joined "Good Morning America" after the State of the Union address to discuss the crisis with Russia and the president's plans for health care, inflation, jobs and education.

When pressed again that Putin appears to be willing to take the cost and is not backing down, Harris insisted: "We're going to do everything that we can to support the Ukrainian people."

"We are doing that through our security assistance, through economic assistance, humanitarian assistance," she added. "We're not going to let up."

Harris dodged a question about whether about whether U.S. intelligence now suggests that Ukraine's capital, Kyiv, will fall to Russian forces.

"This is Putin's war, and we are very concerned and we are monitoring it," she said. "We are fully aware that if there's any intentional targeting of civilians, that we are looking at the fact that there may be a violation, very well may be a violation of international law. So this is an issue that we should all be paying attention to. It is atrocious and it is a violation of all of the standards and principles that we as particularly NATO nations take seriously."

-ABC News Sarah Kolinovsky and Kelly McCarthy

A Russian delegation will be sent to an undisclosed location to await a possible second round of talks with Ukraine on Wednesday, Kremlin spokesman Dmitry Peskov said.

"Our delegation will be waiting for the Ukrainian negotiators on-site this afternoon, closer to the evening," Peskov told reporters Wednesday, noting that he would not be revealing the location for now.

"We can try to predict whether Ukrainian negotiators will show up or not. Let's hope this happens," he added. "Our [negotiators] will be there and ready."

The head of the Russian delegation, Vladimir Medinsky, has said that they would be on the Belarus-Poland border but there's been no confirmation of that location.

Ukraine has not yet confirmed that it will take part in the talks with Russia on Wednesday. Ukrainian Foreign Minister Dmytro Kuleba said earlier that his country was ready to negotiate but that Russia had not changed its position and was still issuing ultimatums.

Wednesday's talks would follow a meeting between both sides near the Belarus-Ukraine border on Monday that failed to reach a breakthrough.

-ABC News' Patrick Reevell

Russian Foreign Minister Sergey Lavrov warned Wednesday that if a third world war were to take place, it would involve nuclear weapons and be destructive, according to Russian state-owned news agency RIA Novosti.