RAMSTEIN AIR BASE, Germany (AP) — U.S. Defense Secretary Lloyd Austin said Thursday President Joe Biden has approved additional military aid to Ukraine worth up to $675 million, an announcement that came as he gathered allies to renew their commitment to military support “for the long haul.”

Austin said at the start of a meeting with senior officials from allied countries at the United States’ Ramstein Air Base in Germany that Biden approved the latest tranche of U.S. assistance on Wednesday.

He said that the package includes howitzers, artillery munitions, Humvees, armored ambulances, anti-tank systems and more.

Austin said that, “The war is at another key moment,” with Ukrainian forces beginning their counteroffensive in the south of the country. He said that, “Now we’re seeing the demonstrable success of our common efforts on the battlefield.”

“The face of the war is changing and so is the mission of this contact group,” Austin told the 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.

“We will work together to train Ukraine’s forces for the long haul. We will work together to help integrate Ukraine’s capabilities and bolster its joint operations for the long haul,” he said. “We will work together to upgrade our defense industrial basis to meet Ukraine’s requirements for the long haul, and we will work together for production and innovation to meet Ukraine’s self-defense needs for the long haul.”

“We must evolve as the fight evolves,” Austin said.

Also on Thursday, U.S. Secretary of State Antony Blinken made an unscheduled visit to Kyiv as the Biden administration announced major new military aid worth more than $2 billion for Ukraine and other European countries threatened by Russia.

In meetings with senior Ukrainian officials, Blinken said the Biden administration would provide $2 billion in long-term foreign military financing to Ukraine and 18 of its neighbors, including NATO members and regional security partners “most potentially at risk for future Russian aggression.”

That’s on top of the package of heavy weaponry, ammunition and armored vehicles for Ukraine alone that Defense Secretary Lloyd Austin announced earlier Thursday at a conference in Germany. That package includes howitzers, artillery munitions, Humvees, armored ambulances, anti-tank systems and more.

Thursday’s contributions bring total U.S. aid to Ukraine to $15.2 billion since Biden took office. U.S. officials said the new commitments were intended to show that American support for the country in the face of Russia’s invasion is unwavering.

The announcements came as fighting between Ukraine and Russia has intensified in recent days, with Ukrainian forces mounting a counteroffensive to retake Russian-held areas in the south and east.

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

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