KYIV, Ukraine (AP) — Underscoring determined U.S. support, Secretary of State Antony Blinken paid an unannounced visit to Kyiv on Thursday and the Biden administration ramped up military aid by more than $2.8 billion to Ukraine and other European countries threatened by Russia.

The new assistance came as the U.S. sought to boost momentum in Ukraine’s counteroffensive against Russia — and amid fears that public support is waning as the war drags on. President Joe Biden, Blinken and Defense Secretary Lloyd Austin all participated in meetings aimed at showing U.S. resolve to stand behind Ukraine.

In Kyiv, Blinken said the administration would provide $2.2 billion in long-term military financing to Ukraine and 18 of its neighbors “potentially at risk of future Russian aggression.” That’s on top of a $675 million package of heavy weaponry, ammunition and armored vehicles for Ukraine alone, announced by Austin and Gen. Mark Milley, chairman of the Joint Chiefs of Staff, earlier in the day.

“I thought it was particularly meaningful (to visit) at this time as Ukraine is starting this counteroffensive in the south, also in the east,” Blinken told reporters in Kyiv before boarding a train for Poland after meeting Ukrainian President Volodomyr Zelenskyy and his top aides.

“It’s early days, but we’re seeing real effectiveness on the ground, and we’re proud of the fact that our support, the support of so many other countries, is helping to enable what the Ukrainians are doing and working to liberate territory seized by Russia in this aggression,” Blinken said.

He told Zelenskyy when they met, “We know this is a pivotal moment, more than six months into Russia’s war of aggression against Ukraine, as your counteroffensive is now underway and proving effective.”

Zelenskyy replied, “We are grateful for the signal, for this enormous support that you’re providing on a day-to-day basis.”

The new funding and military weapons are designed to provide enduring training and support for what Gen. Milley called a “very deliberate” counteroffensive that Ukrainian troops have launched.

Meeting virtually, Biden and the leaders of major U.S. allies all emphasized their countries’ strong support “for Ukraine as it defends itself from Russian aggression,” according to a White House readout.

“Russia’s weaponization of energy” and what to do about it — a major concern for this winter in Europe — was also discussed, said press secretary Karine Jean-Pierre. Those on the call included the leaders of Germany, Italy, the United Kingdom, Poland, Romania, NATO, Canada and Japan and representatives from France and the European Union.

Austin and Milley announced the package of heavy weaponry, ammunition and armored vehicles for Ukraine alone at a conference in Ramstein, Germany.

“We are seeing real and measurable gains from Ukraine in the use of these systems,” said Milley. He said Russia is suffering significant equipment and troop losses. But, he added, “The war is not over. Russia is a big country. They have very serious ambitions with respect to Ukraine. So sustainment of Ukraine to continue their fight for their survival will be necessary.”

The $2.2 billion in so-called Foreign Military Financing has already been appropriated by Congress, but lawmakers, some of whom have expressed concerns about the massive amounts of money going to Ukraine, must still approve the actual allotments. Just two weeks ago, the administration had announced a $3 billion package of support for Ukraine.

About $1 billion of the total will go to Ukraine and the rest will be divided among Albania, Bosnia, Bulgaria, Croatia, the Czech Republic, Estonia, Georgia, Greece, Kosovo, Latvia, Lithuania, Moldova, Montenegro, North Macedonia, Poland, Romania, Slovakia and Slovenia, the State Department said.

It will help those countries “deter and defend against emergent threats to their sovereignty and territorial integrity” by enhancing their military integration with NATO and countering “Russian influence and aggression,” the department said.

Asked about continued congressional support for the massive aid packages, Austin said the administration will provide its rationale to lawmakers, and “I fully expect that it will continue to receive broad bipartisan support because our leaders recognize how important this is.”

Foreign Military Financing allows recipients to purchase U.S.-made equipment, often depending on their specific needs.

The package for Ukraine includes howitzers, artillery munitions, Humvees, armored ambulances, anti-tank systems and more to assist the country with its shorter-term needs as it presses its counteroffensive.

“The capabilities we are delivering are carefully calibrated to make the most difference on the battlefield,” Blinken said.

He will visit NATO headquarters in Brussels on Friday to further emphasize coordinated support. And Austin announced the U.S. will convene a meeting of international senior leaders to discuss how their defense industrial bases can best equip Ukraine’s forces into the future.

“The war is at another key moment,” Austin said. “Now we’re seeing the demonstrable success of our common efforts on the battlefield,” he said at a meeting of the Ukraine Defense Contact Group, which was attended by NATO Secretary-General Jens Stoltenberg and Ukraine’s defense minister as well as officials from allied countries.

Germany and the Netherlands will provide training in de-mining to Ukrainian soldiers as well as de-mining equipment, the countries’ defense ministers said on the sidelines of the meeting with Austin. The training will be carried out in Germany. The two countries previously joined forces to send howitzers.

Thursday’s contributions bring total U.S. aid to Ukraine to $15.2 billion since Biden took office.

Fighting between Ukraine and Russia has intensified in recent days, with Ukrainian forces mounting a counteroffensive to retake Russian-held areas.

Ukrainian forces in the northeastern Kharkiv region have retaken portions of Russian-held territory as efforts in the south have drained some of Moscow’s resources in the area, according to a report from the Washington-based think tank Institute for the Study of War.

Meanwhile, shelling continued near Ukraine’s Zaporizhzhia nuclear power plant, Europe’s largest, with the warring sides again trading blame amid dire warnings from the U.N. atomic watchdog, which has urged the creation of a safe zone to prevent a catastrophe.

Separately, on Wednesday, the U.S. accused Moscow of interrogating, detaining and forcibly deporting hundreds of thousands of Ukrainians to Russia. Russian officials rejected the claim as “fantasy.”

Before leaving Ukraine, Blinken visited the devastated city of Irpin outside Kyiv where he toured damage caused by Russian forces during their 25-day occupation. He was told there that Ukrainian investigators have 30,000 open cases related to war crimes.

“There has to be accountability for those who committed atrocities” he said.

Before meeting Zelenskyy and Ukrainian Foreign Minister Dmytro Kuleba, Blinken made a short stop at the U.S. Embassy and then the National Specialized Children’s Hospital Ohmatdyt, where he saw boys and girls injured during Russian bombardments, including Maryna, a 6-year-old from the city of Kherson who lost a leg after a rocket struck her house.

In the hospital lobby, Blinken also met Patron, a Jack Russell terrier that has helped Ukraine’s military find more than 200 mines laid by Russian forces. Blinken knelt down, petted the dog and presented him with treats, saying he was “world famous.”

In one ward, Blinken brought a basket of stuffed animals, which the children quickly dangled in front of Patron to get his attention.

Blinken told parents that “the spirit of your children sends a very strong message around the world.”

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AP Diplomatic Writer Matthew Lee reported from Rzeszow, Poland. Lolita C. Baldor contributed from Washington.

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