The Ukrainian armed forces have received approximately 3,000 applications from the U.S. to join the fight against invading Russian troops, a Ukrainian Embassy official confirmed to ABC News.

Voice of America was first to report the news this weekend.

-ABC News’ Conor Finnegan

In a new letter to House Democrats, Speaker Nancy Pelosi reiterated plans to approve new aid for Ukraine in a government funding measure this week.

She also said new legislation to ban the import of Russian oil and energy products would repeal normal trade relations with Russia and Belarus and deny Russia access to the World Trade Organization.

The measure would also give the administration more power to raise tariffs on Russian imports.

Pelosi said Congress and the Biden administration “remain laser-focused on bringing down the higher energy costs for American families and our partners,” noting that 60 million barrels of oil have been released from strategic reserves and allies have said they will reduce their dependence on Russian energy.

“With the West’s carefully coordinated effort to sequence sanctions on Russia and mitigate for the costs of these efforts, we are standing up for our values abroad while protecting our families at home,” Pelosi wrote in the letter.

It’s not clear when the House will take up this measure, but Congress needs to approve government funding -- which will include the Ukraine aid -- by Friday.

-ABC News’ Ben Siegel

A planned Russian strike targeting military-industrial facilities will result in countless civilian casualties, Ukrainian President Volodymyr Zelenskyy warned in a new address.

He began his latest speech by saying that on a day recognized by Ukrainians as “Forgiveness Sunday,” there will be no forgiveness for Russia.

“We will not forgive shooting our people and destroying our infrastructure. Hundreds upon hundreds of victims, immeasurable suffering. God will not forgive this, not today, nor tomorrow, never,” Zelenskyy said.

The Russian Ministry of Defense announced on Sunday it will use high-precision weapons to destroy Ukrainian military-industrial facilities.

Zelenskyy warned those sites are in urban areas surrounded by civilian residences. “Hundreds of thousands of people live and work there,” he said. “This will be a premeditated murder, but today I haven’t heard any reaction from any world leader or any politician.”

He said Russia was openly announcing a “planned atrocity” in advance because there is no reaction from the international community.

“Well, I hope you’ll at least say something tomorrow when you’ll see it happened,” Zelenskyy said. “We know exactly how these attacks will be carried out, we know the full chain of command, we know everything, and we’ll forgive nothing.”

-ABC News’ Christine Theodorou

Approximately 600 Russian missile launches have taken place since the invasion of Ukraine began on Feb. 24, a senior defense official said.

They could not corroborate any reports of the use of cluster munitions or thermobaric weapons.

Ukrainian air and missile defenses are still effective and in use, the official said, though the airspace over Ukraine is contested.

Both sides have taken losses to aircraft and missile defense inventories, the defense official added, and while they did not reveal exact numbers, they believe both Russia and Ukraine still have a majority of their air defense systems.

The official also said Russian forces are still trying to advance across the north and east of Ukraine but are being met with strong Ukrainian resistance. The convoy is still stalled.

-ABC News’ Matthew Seyler

U.S. Secretary of State Antony Blinken crossed the border into Ukraine Saturday after meeting with Ukrainian Foreign Minister Dmytro Kuleba at the Korczowa Border Crossing Point.

"The entire world stand with Ukraine," Blinken said, and Kuleba added that he hopes Ukrainians will see this as a "clear manifestation that we have friends who literally stand by us."

Blinken said the sanctions imposed so far against Russia are "producing very, very concrete results" and that the pressure will "grow" until this "war of choice is brought to an end."

When asked directly about helping Kuleba with more firepower, Blinken said, "the support for Ukraine not only has been unprecedented, not only is going to continue, it's going to increase."

Kuleba said Ukraine "appreciates" sanctions that have been announced in the last week, but that more economic and political pressure and "necessary weapons," would "save many lives in Ukraine... many sufferings will be avoided."

Kuleba also said that they are “satisfied" with already arranged supplies of anti-tank weapons and ammunition, but that “it’s no secret” they still want fighter jets and air defense systems.

He also thanked the U.S. for sending stingers, and said they were used on Saturday.

"Just today we shot down three Russian attack aircrafts, which were bombing our cities with the use of stingers but we need -- so to say -- big air defense systems to ensure the safety of our skies. If we lose the skies, there will be much, much more blood on the ground,"Kuleba said.

In response to questions about NATO’s refusal to impose a no-fly zone over Ukraine, Kuleba said it’s a "sign of weakness," but stayed optimistic that they will change their minds.

"The time will come," he said.

-ABC News' Conor Finnegan and Justin Gomez