Cuban officials announced Monday that they have "detected" and are "working on the neutralization and dismantling of a human trafficking network that operates from Russia to incorporate Cuban citizens living there, and even some from Cuba, into the military forces participating in war operations in Ukraine."

"Attempts of this nature have been neutralized and criminal proceedings have been initiated against people involved in these activities," the Cuban Ministry of Foreign Affairs said in a statement.

The ministry noted that "Cuba has a firm and clear historical position against mercenarism and plays an active role in the United Nations in repudiation of this practice."

"Cuba is not part of the war in Ukraine," the ministry added. "It is acting and will act energetically against anyone, from the national territory, who participates in any form of human trafficking for the purpose of recruitment or mercenarism for Cuban citizens to use arms against any country."

-ABC News' Mara Valdes

Ukraine’s President Volodymyr Zelenskyy has asked the country’s parliament to replace the country’s current Minister of Defense.

In a Sunday address, Zelenskyy told the Ukrainian people they need new approaches for the military and Rustem Umerov is the person he wants in the minister job. Current minister Oleksiy Reznikov has served throughout the conflict with Russia.

Additionally, Zelenskyy announced he had reached an agreement with French President Emmanuel Macron. Though he did not go into details, Zelenskyy mentioned the agreement is related to training Ukrainian pilots in France.

-ABC News' Ellie Kaufman

Russian officials are claiming a drone attack on the Bryansk region by Ukraine, the second such attack in the country in as many nights. Two drones were allegedly shot down by air defense in the city, according to local officials.

One of the Ukrainian kamikaze drones that attacked Bryansk fell on the hotel of the Department of Affairs of the regional government, about 100 meters from the building of the regional administration, according to multiple local officials.

Meanwhile, Russia claimed it repelled a drone attack on the Moscow region. The drone attack Thursday morning caused no casualties or destruction in the Voskresensk district of the Moscow region, the district's head, Alexei Malkin, said.

"No traces of destruction have been discovered thus far. No one was injured. All emergency services are working at the scene," Malkin said on his Telegram channel.

"On-duty air defenses destroyed the unmanned aerial vehicle over the Voskresensk district of the Moscow region," the ministry said.

-ABC News' Will Gretsky

The Kremlin on Wednesday acknowledged for the first time that a plane carrying Yevgeny Prigozhin, mercenary chief of the paramilitary Wagner Group, was possibly downed on purpose.

Kremlin spokesman Dmitry Peskov told reporters that investigators are looking into the possibility that the 62-year-old Prigozhin was assassinated.

"It is obvious that different versions are being considered, including the version -- you know what we are talking about -- let's say, a deliberate atrocity," Peskov said when asked about the investigation.

The plane carrying Prigozhin and nine others crashed in Russia's Tver region on Aug. 23, killing everyone aboard, according to the press service of Russia's Federal Air Transport Agency.

The crash came about a month after Prigozhin led a chaotic armed rebellion that threatened the longstanding leadership of Russian President Vladimir Putin.

On Friday, Peskov denied speculation that the Kremlin was involved in the plane crash, calling the allegation an "absolute lie."

The crash investigation is being conducted by the Russian Investigative Committee as a domestic incident and Peskov said that allowing in international investigators "is out of the question."

-ABC News' Will Gretsky

The United States "is prepared to defend every inch of NATO territory," National Security Advisor Jake Sullivan said Wednesday, amid Russia's threats of military retaliation if Sweden and Ukraine officially join the alliance.

"At the end of the day, Russia does not get a vote in who joins NATO," Sullivan told ABC News' George Stephanopoulos during an interview Wednesday on "Good Morning America."

"If Russia does choose to test Article 5, President Biden has said he is prepared to defend every inch of NATO territory," he added. "And later tonight, when he addresses a large crowd in Vilnius in a speech about his vision for Euro-Atlantic security and for American leadership, he will reinforce this point about the sanctity of Article 5."

Article 5 of the NATO treaty states that the signed parties "agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all."

Sweden and Finland, which have historically embraced neutrality, applied for NATO membership together last year despite warnings from Moscow against doing so, as Russian forces invaded Ukraine. Finland officially joined the alliance in April following Turkish ratification, but Turkey and Hungary have yet to ratify Sweden’s membership. NATO Secretary-General Jens Stoltenberg announced Monday that Turkish President Recep Tayyip Erdogan has agreed to send Sweden’s NATO accession documents to Turkey’s Parliament for approval "as soon as possible," one of the last steps in the membership process.

Meanwhile, Ukraine is pushing hard for NATO membership as Russia’s war presses on. Stoltenberg announced Tuesday that the bloc "will issue an invitation for Ukraine to join NATO when allies agree and conditions are met," pledging to speed up the process by eliminating bureaucratic hurdles, but without offering a timeline.

"All 31 allies got together yesterday to say with one voice that Ukraine's future is in NATO. The real question is just how we work down the pathway to get them in," Sullivan told ABC News on Wednesday. "So the signal that NATO sent yesterday was very positive to Ukraine about its future prospects for joining NATO, and we will work in terms of the democratic and security sector reforms that are necessary. And in the meantime, we're not just going to sit around. We're going to provide Ukraine with the weapons and military assistance it needs to defend its territory against Russia and to deter future aggression from Russia."

Ukraine has requested F-16 fighter jets and long-range missiles to aid its counteroffensive against Russian forces. Sullivan said the U.S. has already taken steps with NATO allies to begin the training of Ukrainian pilots on F-16s, which "will take some time," and then the aircraft will be transferred to Ukraine "likely from European countries that have excess F-16 supplies." As for the long-range missiles, Sullivan said the U.S. will continue to look into the issue and discuss it with Ukraine.