US Secretary of State Antony Blinken made an unannounced diplomatic visit to Kiev.
"We recognize that we are going through a difficult time," said Blinken, who met with President Volodymir Zelensky in Kiev to reassure Ukraine that it has American support.
The visit comes after the US Congress approved a long-delayed foreign aid package for Ukraine that includes $60 billion in aid.
Blinken, making his fourth visit to Kiev since Russia invaded Ukraine in February 2022, said aid from the new package was "now on its way" and that some of it had already arrived in Ukraine.
National Security Adviser Jake Sullivan said the US was "really trying to accelerate the pace" of arms shipments to Ukraine. "I would say that the level of intensity right now in terms of the transportation of materiel is 10 out of 10," Sullivan said.
Since President Joe Biden signed the aid package late last month, the administration has announced $1.4 billion in short-term military aid and $6 billion in long-term support, officials said.
Blinken told CBS television, "We're not going anywhere. Neither are the more than 50 countries that support Ukraine. This will continue, and if Putin thinks he can outlast Ukraine and its supporters, he's wrong."
