The U.S. will announce $3 billion more in arms for Ukraine on Wednesday, when the country will mark a tense Independence Day and six months since Russia’s invasion, according to a US official. 

US diplomats warned that Russia is preparing intensified attacks on Ukraine’s civilian infrastructure and government facilities in  coming days, and Ukrainian President Volodymyr Zelenskiy has said the Kremlin may attempt a “particularly cruel” assault.

Zelenskiy also reinforced a pledge to drive Russian occupiers from Crimea, which Moscow annexed in 2014. 

The Ukrainian leader also denied any role in the car bomb that killed Darya Dugin, the daughter of a Russian nationalist, after Russian authorities accused Ukrainian special services of orchestrating the killing. Russian President Vladimir Putin called the assassination a “dastardly crime.”