KYIV, Ukraine (AP) U.S. Secretary of State Antony Blinken arrived in Kyiv on Tuesday in an unannounced diplomatic mission to reassure Ukraine that it has American support as it struggles to defend against increasingly intense Russian attacks .

We know this is a challenging time, Blinken said in the Ukrainian capital where he met with President Volodymyr Zelenskyy.

The visit comes less than a month after Congress approved a long-delayed foreign assistance package that sets aside $60 billion in aid for Ukraine , much of which will go toward replenishing badly depleted artillery and air defense systems.

Assistance from the new package is now on the way, Blinken said, adding that some of it has already arrived in Ukraine.

He said the aid would make a real difference on the battlefield where Russias army has in some areas seized the initiative against Kyivs depleted forces.

On his fourth trip to Kyiv since Russia invaded Ukraine in February 2022, Blinken will underscore the Biden administrations commitment to Ukraines defense and long-term security , U.S. officials said. They noted that since President Joe Biden signed the aid package late last month, the administration has already announced $1.4 billion in short-term military assistance and $6 billion in longer-term support.

It is trying to really accelerate the tempo of U.S. weapon shipments to Ukraine, national security adviser Jake Sullivan said.

What I am going to suggest is that the level of intensity being exhibited right now in terms of moving stuff is at a 10 out of 10, Sullivan told reporters at a White House briefing Monday.