WATCH: Deadly Ukraine market attack overshadows Blinken visit😳

Over a dozen people were killed in a reported Russian attack on an eastern Ukrainian city on Wednesday (September 6).

The attack overshadowed a visit by U.S. Secretary of State Antony Blinken on the same day.

Blinken travelled to Kyiv to offer support for its

counteroffensive against Russia's invasion forces.

President Volodymyr Zelenskiy condemned the attack, which hit a market, shops and a pharmacy in the city of Kostiantynivka, as, quote "Russian evil."

He said a child was among those dead, and many people were wounded.

Blinken is expected to announce a new package of U.S. wartime assistance worth over $1 billion during his two-day visit.

That's according to a senior State Department official.

"I am here in large part at the behest of President Biden to reaffirm our commitment to stand with you, to stand with you to help ensure that you succeed militarily in dealing with the aggression, but also to stand with you to make sure that your efforts to build a strong economy and a strong democracy succeed."

Blinken's visit marks the first top U.S. official to visit Kyiv since the counteroffensive began in early June.

The U.S. official said Washington wanted to discuss how the counteroffensive was going and assess battlefield needs.

As well as any steps required to fortify Ukraine's energy security before winter.

In response, Kremlin spokesman Dmitry Peskov said Moscow believed Washington planned to continue funding Ukraine's military "to wage this war to the last Ukrainian."

He said U.S. aid to Kyiv would not affect the course of what he called Russia's special military operation.