The U.S. Department of Defense announced a new $325 million military aid package for Ukraine, including more rockets and artillery rounds, in addition to other equipment.

Defense Secretary Lloyd Austin and Gen. Mark Milley are in Europe to attend another meeting of the 50-plus countries providing military assistance to Ukraine that begins later this week in Ramstein, Germany.

"The United States will continue to work with its Allies and partners to provide Ukraine with capabilities to meet its immediate battlefield needs and longer-term security assistance requirements," the Pentagon said in a statement.

-ABC News' Luis Martinez

The German government announced Tuesday that it delivered a Patriot missile defense system and missiles to Ukraine this week.

The country also sent 16 Zetros trucks, bringing its total to 76, and two border patrol vehicles, bringing its total to 124, the government said.

-ABC News' Will Gretsky

Russia's security services have arrested an anti-Kremlin political commentator who the jailed Wall Street Journal reporter Evan Gershkovich met with shortly before his own arrest.

Yaroslav Shirshikov has said he spent two days showing Gershkovich around the city of Yekaterinburg during a reporting trip there a couple of weeks before Russia seized Gershovich.

Shirshikov said he had been due to meet with Gershkovich again the week the reporter was arrested in the city.

This morning, local media published video showing masked security officers detaining Shirshikov in his apartment and searching it.

A local news outlet cited a security services representative saying Shirshikov may have been arrested for posting comments cheering the assassinations of two ultra-nationalist pro-war figures, Daria Dugina and the blogger Vladen Tatarsky.

The site UralLive quoted a law enforcement source that Shirshikov was detained on a charge of “justifying terrorism”, which carries a maximum sentence of 7 years prison. It linked the charge to a social media post in which Shirshikov wrote he wasn’t sad over the death of Tatarsky, who was killed in a bomb attack in St. Petersburg this month.

Shirshikov spoke to several international media outlets including ABC following Gershkovich's arrest. He said that Gershkovich had acted entirely as a professional journalist in Yekaterinburg, conducting interviews openly and doing usual reporting.

Shirshikov is a critic of the Russian government and has spoken publicly about his opposition to the war in Ukraine.

-ABC News' Patrick Reevell

Russian President Vladimir Putin made a trip to Kherson and Luhansk, visiting a military headquarters in occupied territory in Ukraine.

Putin arrived via helicopter at the headquarters of an army group in occupied Kherson, according to video released on Tuesday by the Kremlin.

In brief remarks after he arrived, Putin said he didn't want to distract troops from their mission, saying his tour of the installation would be in a "businesslike manner, briefly, but concretely," according to Interfax, a Russian state-affiliated news wire.

"It is important for me to hear your opinion on how the situation is developing, to listen to you, to exchange information," he said, according to Interfax.

-ABC News' Joe Simonetti

A Moscow court has sentenced one of Russia's best-known opposition leaders, whose family live in the U.S., to 25 years in prison in what is widely seen a show trial.

Vladimir Kara-Murza is the most high-profile opponent of Russian President Vladimir Putin to be jailed since Alexey Navalny.

Kara-Murza's extraordinarily harsh sentence is one of the lengthiest any opposition figure has received under Putin and illustrates how repressive Russia has become during the war in Ukraine, reverting to something much closer to the USSR where no opposition is tolerated.

Kara-Murza was convicted of treason, as well as "discrediting Russia's armed forces," a new law that effectively criminalizes criticizing the war in Ukraine. He was also convicted of belonging to a banned organization. The charges are widely seen as politically motivated.

Kara-Murza is one of Russia's best-known pro-democracy figures and a veteran critic of Putin.

Kara-Murza, who holds both British and Russian citizenship, spent many years living in the United States and his wife and children still live in Virginia. He was close to the late U.S. Sen. John McCain, who championed human rights in the former Soviet Union.

Dozens of journalists and Western diplomats attended the court hearing on Monday, including the U.S. ambassador who read out a statement condemning the sentence.

"We support Mr. Kara-Murza and every Russian citizen to have a voice in the direction of their country. Mr. Kara-Murza and countless other Russians believe in and hope for a Russia where fundamental freedoms will be upheld. And we will continue to share those hopes and work for that outcome," Amb. Lynne Tracy said.

Kara-Murza previously has survived being poisoned not once but twice. In 2015 and then again in 2017, he suffered organ failure after being exposed to an unknown toxin. Independent researchers later linked the poisoning to the same team of FSB poisoners who targeted Navalny.

He chose to return to Russia after the war began, believing it was important to continue to campaign for freedom in his country and has been an outspoken critic of the invasion.

His trial was held entirely behind closed doors, but a letter containing his closing statement to the court has been released to reporters.

"I only blame myself for one thing," Kara-Murza said in the statement. "I failed to convince enough of my compatriots and politicians in democratic countries of the danger that the current Kremlin regime poses for Russia and for the world."

"Criminals are supposed to repent of what they have done. I, on the other hand, am in prison for my political views. I also know that the day will come when the darkness over our country will dissipate.

-ABC News' Patrick Reevell