The United States will back Ukraine until its security is “guaranteed,” US Secretary of State Antony Blinken said on a trip to Kyiv on Tuesday, hours after Russian forces claimed further advances in the northeastern Kharkiv region.

Blinken’s visit comes just weeks after the US Congress finally approved a $61-billion financial aid package for Ukraine following months of political wrangling, unlocking much-needed arms for the country’s outgunned troops.

“The assistance is now on its way. Some of it has already arrived. More will be arriving,” Biden had told Ukrainian President Volodymyr Zelensky during a meeting earlier.

Zelensky thanked Washington for the aid, which he said was “crucial” – but stressed it was “important to get it as quickly as possible.”

Zelensky said air defense was the “biggest problem” for Ukraine and requested two Patriot batteries for the Kharkiv region, where Russian forces have been advancing and pounding villages along the border since Friday.

‘Minimal human losses’

Russia’s surprise ground offensive in the Kharkiv region has forced thousands to evacuate and pushed Kyiv to mobilize troop reinforcements.

In a call to Zelensky, French President Emmanuel Macron condemned the “intensification of Russian strikes” and the Kharkiv offensive.

Russia’s Defense Ministry, meanwhile, said its forces had captured another village in the Kharkiv region.

The advance is the latest in a string of tactical successes for Russia on the battlefield this year after initial setbacks in a conflict that Russia hoped would be wrapped up in days.

Russia’s incoming Defense Minister, economist Andrei Belousov, said that Moscow’s priority was to secure victory on the battlefield against Ukraine while minimizing human losses.

The head of Ukraine’s security council, Oleksandr Lytvynenko, said Moscow had massively upped its troop deployment for the new offensive in the Kharkiv region. In an interview this week with AFP, he said Russia had sent more than 30,000 troops over the border. But he added that there was no threat of an assault on Kharkiv, Ukraine’s second-largest city.