KYIV, Ukraine>> Germany’s top diplomat arrived Monday in the Ukrainian capital on an unannounced visit, in what appeared to be a show of European support for Ukraine on the eve of a U.S. presidential election that could bring far-reaching changes in Washington’s policy toward Russia’s all-out invasion of its neighbor.

Germany is Ukraine’s second-biggest weapons supplier after the U.S. Foreign Minister Annalena Baerbock vowed that Berlin’s backing would remain steadfast.

“Together with many partners around the world, Germany stands firmly by Ukraine’s side,” she said, German news agency dpa reported. “We will support the Ukrainians for as long as they need us so that they can continue on their path to a just peace.”

The war is at a critical moment for Ukraine, with the Russian army making creeping gains on the battlefield and another hard winter ahead after Russia relentlessly battered the Ukrainian power grid.

With his army under severe Russian pressure in the eastern Donetsk region, Ukraine President Volodymyr Zelenskyy said Monday that Western military aid deliveries have accelerated, including for artillery.

The grinding attritional warfare being fought in Ukraine requires large amounts of ammunition, and Ukrainian officials have long grumbled that Western pledges of support take too long to arrive.

Zelenskyy said Ukraine is also trying to strengthen its air defense systems. Russia is currently deploying about 10 times more Iranian-made Shahed drones than it was this time last year, he said.

Ahead of the U.S. election, Zelenskyy attempted to lock Ukraine’s Western supporters into a long-term “victory plan,” including a formal invitation for Ukraine to join NATO and permission to use Western long-range missiles to strike military targets in Russia, but the response was disappointing for Kyiv officials.

Russia is using its superior numbers to heap pressure on Ukrainian positions along the front line. Ukraine’s top commander, Gen. Oleksandr Syrskyi, said Saturday his troops struggled to hold back “one of the most powerful (Russian) offensives” of the war.

Russia is now adding to its offensive push what U.S., South Korean and Ukrainian intelligence assessments say is a total of about 10,000 to 12,000 North Korean combat troops sent by Pyongyang under a pact with Moscow.

U.S. State Department spokesman Matthew Miller told reporters Monday that as many as 10,000 North Korean soldiers were in Russia’s Kursk region near Ukraine’s border and preparing to join Moscow’s fight against Ukraine in the coming days. That’s up from 8,000 troops that the U.S. government mentioned Thursday.

That has deepened Zelenskyy’s frustration with Western help. On Saturday, he urged allies to stop “watching” and take steps before the North Korean troops reach the battlefield.

Zelenskyy said Kyiv knows at which Russian camps the North Korean troops are being trained but Ukraine can’t strike them without permission from allies to use the Western-made long-range weapons to hit targets deep inside Russia.

Baerbock arrived in Kyiv hours after debris from drones intercepted by air defenses fell in two districts of the city, starting small fires, officials said. No people or property were harmed, according to the head of the Kyiv city administration, Serhii Popko.