To which countries did the Ukrainian refugees go? 1:04 (CNN) — The war in Ukraine may be entering a critical new phase with a new focus by Russia’s military, one last battle in a key Ukrainian city and the promise of additional US firepower to fight the war. help Ukraine fight back. New focus. Russia’s military is now concentrating on the disputed eastern part of Ukraine that was thought to be its target before the invasion began. British intelligence suggests that Ukrainian forces have repelled numerous advance attempts by Russian forces in the area, but US officials warn that the Russians may be preparing for a larger attack in southeastern Ukraine. Ukrainian poplar. Russian advances in the south against besieged defenders in the city of Mariupol, a key supply hub, are dimming hopes for Ukraine’s armed forces after the commander made a desperate plea for help. Ukraine’s government says women and children are also seeking refuge in a steel plant that is the military’s stronghold. More weapons are coming. The United States is considering a new injection of weapons to help Ukraine adjust to a different stage of the conflict. The Biden administration believes the war is at a critical stage and is looking for ways to support Ukraine’s military. Another $800 million in aid? CNN’s White House and Pentagon teams report that the Biden administration may send another $800 million military assistance package to Ukraine, on top of the $800 million announced last week. Size and details could change. A senior administration official told CNN Tuesday that the package could arrive within the next 36 hours, but another administration official said the time is not closed. Separately, the parts have helped Ukraine add about 20 planes to its air force, a senior US defense official said on Wednesday, though it was unclear where the parts came from. Grand total: Would add a total of $3.4 billion in US assistance to Ukraine since the invasion began, if the second $800 million package is approved. What is being sent to help in the East? Artillery and long-range systems might be more useful in more open terrain. This is the same disputed region of Donbas where Russian-backed forces have been fighting the Ukrainian army for years. A Ukrainian man searches for the father of his missing Russian invasion 3:18 What about all this firepower? It is not entirely clear. An interesting CNN report focused on how the United States loses track of the weapons it sends to Ukraine. From the CNN report: In making the decision to send billions of dollars worth of weapons and equipment to Ukraine, the Biden administration took into account the risk that some of the shipments might end up in unexpected places, a defense official said. But right now, the official said, the administration sees failing to properly arm Ukraine as a bigger risk. I asked CNN’s Oren Liebermann, who helped write the two stories on US military aid, what would happen to all these additional weapons that were probably headed from the US to Ukraine. Pay attention to the importance of artillery, he told me. It’s expected to be a big part of the next shipment, and it was a major (albeit much smaller) part of the last $800 million package. Why hadn’t more artillery been sent? LIEBERMANN: Because artillery was not the kind of weapon needed to defend Kyiv. In the swamps and forests of northern Ukraine, not to mention the Chernobyl exclusion zone, artillery was not a critical part of the fighting. With the focus now on southeastern Ukraine, artillery and other long-range weapons are absolutely critical. Is this new technology or a game changer in battle? LIEBERMANN: Let’s be clear: artillery is not a new technology. Perhaps the systems are newer and offer a little more accuracy or more firepower, but artillery is not a novel piece of military hardware that has never been seen before. Quite the contrary: It has been an integral part of warfare for many, many decades, if not a couple of centuries at this point. And yet, the US and its partners/allies see it as one of the most important pieces of weaponry to get to Ukraine…and fast. Ukraine can burn through artillery ammunition quickly, so it’s important to get them a very large supply as soon as possible. How does the Pentagon view its responsibility once these weapons are in Ukraine? LIEBERMANN: That is not considered critical. The Department of Defense’s job is to get it to the border, then Ukraine gets it from there to wherever it thinks it’s needed. Ukraine has an almost insatiable appetite right now for more weaponry, and that is what the United States is trying to satisfy, along with help from other countries. What do we know about what has been shipped so far? According to CNN’s Ellie Kaufman, a senior US defense official told reporters Wednesday that the first of 40,000 rounds of howitzer, a type of artillery ammunition, has arrived in Europe to be shipped to Ukraine. These are part of the most recent $800 million package. The United States is training about 50 Ukrainians in a country outside Ukraine (it is not clear which one) on how to use the Howitzer guns. “This is to train the trainers – it’s a small number of Ukrainians, a little more than 50 – they will be trained on how to use the howitzers, and then they can go back to Ukraine and train their colleagues,” the official said. The NATO issue looms. Finland and Sweden are now actively considering joining NATO, so if Russian President Vladimir Putin’s plan was to stop the growth of the alliance, it has officially failed. Russia has warned that such moves could lead to a more aggressive posture regarding its hypersonic or nuclear weapons. Setback for Putin: Sweden and Finland accelerate their entry into NATO 5:52 Saber rattling. An intercontinental ballistic missile test carried out by Russia on Wednesday is a message to countries trying to threaten it, according to Putin. Abandonment. Russia was further isolated from the world community after Western financial officials, including the US Treasury secretary, walked out of a closed-door meeting of the Group of 20 industrialized nations in Washington rather than listen to a Russian presentation. What is the nuclear threat in Ukraine? CNN’s Barbara Starr and Zachary Cohen report that the US military keeps a constant eye on Russia’s nuclear arsenal. The US has seen no indication that Russia has moved to ready its nuclear arsenal for use, and Starr and Cohen report that US officials still feel there is a very remote chance that Putin will cross that line. But Ukraine’s President Volodymyr Zelensky warned last week that the world must prepare for the possibility that Putin could use nuclear weapons. From Starr and Cohen: Highly classified US military plans continue to be updated on what everyone believes to be an almost unthinkable scenario: the use of a nuclear weapon. The US military “has planned all of this,” a senior defense official said. Final note: Life on the front lines in the Russian Army. CNN’s Phil Black went to an abandoned Russian military camp on the outskirts of Kyiv. When the soldiers failed to take the Ukrainian capital, they were left to live in primitively dug trenches. Black speaks with civilians who were captured and tortured by the Russians, as well as a priest who was asked to bury the people they killed. He sees the video report of him here.