Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

President Joe Biden has announced $1 billion more in U.S. military aid for Ukraine.

Biden said he spoke with Ukrainian President Volodymyr Zelenskyy Wednesday morning and that the aid will include "additional artillery and coastal defense weapons, as well as ammunition for the artillery and advanced rocket systems."

Biden also announced $225 million in humanitarian assistance "to help people inside Ukraine, including by supplying safe drinking water, critical medical supplies and health care, food, shelter, and cash for families to purchase essential items," according to a statement.

-ABC News' Justin Ryan Gomez

President Joe Biden said on Tuesday the United States is working with European allies to remove blocked Ukrainian grain by rail.

Speaking at the 29th AFL-CIO Quadrennial Constitutional Convention, Biden said 20 million tons of grain are stuck in Ukraine and need to be exported to reduce global food prices.

As the grain cannot be exported via the Black Sea due to the constant threat of Russian attacks and explosions, the U.S. and its partners are planning to build granaries on the Ukrainian border, Biden said.

The railways present an alternative to Ukrainian coastal waters of the Azov and Black seas that are in need of demining. The area of their contamination with explosives can be up to 19 thousand square kilometers, Ministry of Internal Affairs spokesperson Alyona Matveeva said on Tuesday.

The full demining of Ukraine can take from 5 to 10 years with the help of international experts, Matveeva added. To date, about 80% of explosive devices have been removed and neutralized in the Kyiv region, she said.

-ABC News' Edward Szekeres, Nataliia Kushnir, Max Uzol and Yulia Drozd

As Russia's stock of modern high-precision missiles depletes, its invading forces are turning to obsolete Soviet models to strike targets in Ukraine, Yuriy Ignat, spokesperson for the Ukrainian Air Force, said at a press briefing on Tuesday.

"Recently, there has been a tendency for Russia to save high-precision, expensive missiles. And now the enemy is increasingly using Soviet types of missiles,” Ignat said.

Some of these missiles are extremely powerful, the spokesman added, and their destructive parts can weigh up to 900 kilograms.

“Their main drawback is that they do not always fly at their intended target and very often destroy civilian objects with human casualties.”

According to Ignat, Ukrainian anti-aircraft missile forces have shot down more than 500 enemy air targets since the start of the full-scale Russian invasion. These include Russian cruise missiles, UAVs, planes and helicopters.

Arnold Schwarzenegger, the former Governor of California, weighed in on the question of Russian missiles on Tuesday when he said that Europe is partly to blame for financing Russia's war against Ukraine.

Addressing a climate conference in Vienna via a livestream, Schwarzenegger said the about 1,300 missiles Russia fired into Ukrainian cities during the first two months of the war cost 7.7 billion euros.

“Now that’s a lot. But during the same time, Europe sent to Russia 44 billion euros for fuel,” the former governor told attendees of the Austrian World Summit. “We have blood on our hands, because we are financing the war. We have to stop lying to ourselves.”

On the other end of the frontline, Ukraine is also grappling with a pressing lack of weapons. The Ukrainian forces received only 10% of the weapons “we said we needed,” Ukrainian Deputy Defense Minister Hanna Malyar told local media on Tuesday.

“Now matter how much effort Ukraine makes, we will not be able to win the war without the help of the West,” Malyar added.

The deputy minister said Ukrainian fighters can afford to spend only about 6,000 shells a day, while the Russians use about ten times more. The limited number of available weapons and ammunition is crippling Ukraine's ability to launch a counteroffensive at the front, military expert Oleh Zhdanov said, according to local outlets.

Speaking at an online press conference for Danish media on Tuesday, Ukrainian President Volodymyr Zelenskyy repeated his plea for Western weapons that he said are vital for the liberation of occupied territories.

The speed of de-occupation “depends on the supply of weapons to Ukraine, and any delays in this matter threaten stagnation on the front,” Zelenskyy said.

Meanwhile, Russian President Vladimir Putin likely still wants to capture much if not all of Ukraine but has had to narrow his tactical objectives in war, Under Secretary of Defense for Policy Colin Kahl said on Tuesday, according to Reuters.

"I still think he has designs on a significant portion of Ukraine, if not the whole country. That said, I do not think he can achieve those objectives," Kahl said, speaking at an event hosted by the Center for New American Security.

-ABC News' Edward Szekeres, Nataliia Kushnir, Max Uzol and Yulia Drozd

Russian and Belarusian tennis players, who are banned from Wimbledon, will be allowed to compete in this year's U.S. Open, but only under a neutral flag, the U.S. Tennis Association said.

The USTA said it "previously condemned, and continues to condemn, the unprovoked and unjust invasion of Ukraine by Russia."

Russian player Daniil Medvedev, the current No. 1 player in the world, won last year's U.S. Open.