KYIV, April 26 - The U.S. pressed its allies Tuesday to move “heaven and earth” to keep Kyiv well-supplied with weapons as Russian forces rained fire on eastern and southern Ukraine amid growing new fears the war could spill over the country’s borders, The Associated Press reported.

For the second day in a row, explosions rocked the separatist region of Trans-Dniester in neighboring Moldova, knocking out two powerful radio antennas close to the Ukrainian border. No one claimed responsibility for the attacks, but Ukraine all but blamed Russia.

Two months into the fighting, Western arms have helped Ukraine stall Russia’s invasion, but the country’s leaders have said they need more support fast.

U.S. Defense Secretary Lloyd Austin convened a meeting Tuesday of officials from about 40 countries at the U.S. air base at Ramstein, Germany, and said more help is on the way.

“This gathering reflects the galvanized world,” Austin said, adding that he wanted officials to leave the meeting “with a common and transparent understanding of Ukraine’s near-term security requirements because we’re going to keep moving heaven and earth so that we can meet them.”

After unexpectedly fierce resistance by Ukrainian forces thwarted Russia’s attempt to take Ukraine’s capital, Moscow now says its focus is the capture of the Donbas, the mostly Russian-speaking industrial region in eastern Ukraine.

Russian advances and heavy fighting were reported in the Donbas, with one town, Kreminna, apparently falling after days of street-by-street fighting, according to the British military.

In the gutted southern port city of Mariupol, authorities said Russian forces hit the Azovstal steel plant with 35 airstrikes over the past 24 hours. The plant is the last known stronghold of Ukrainian fighters in the city. About 1,000 civilians were said to be taking shelter there with an estimated 2,000 Ukrainian defenders.

Ukraine also said Russian forces shelled Kharkiv, the country’s second-largest city, which lies in the northeast, outside the Donbas, but is seen as key to Russia’s apparent bid to encircle Ukrainian troops in the Donbas from the north, east and south.

With the potentially pivotal battle for the east underway, the U.S. and its NATO allies are scrambling to deliver artillery and other heavy weaponry in time to make a difference.

German Defense Minister Christine Lambrecht said her government will supply Gepard self-propelled armored anti-aircraft guns to Ukraine. German Chancellor Olaf Scholz has faced mounting pressure to send heavy weapons such as tanks and other armored vehicles.

U.S. Defense Secretary Lloyd Austin noted that more than 30 allies and partners have joined the U.S. in sending military aid to Ukraine and that more than $5 billion worth of equipment has been committed.

The U.S. defense secretary said the war has weakened Russia’s military, adding, “We would like to make sure, again, that they don’t have the same type of capability to bully their neighbors that we saw at the outset of this conflict.” (ap/ez)