There is no doubt that the US has been vocal in pledging their support towards Ukraine since the whole conflict with Russia began a year ago. However, the timing of Biden's visit today, while fitting with the occasion, may perhaps be a case of sending a message to the opposition. And no, the opposition isn't Russia.
It may be a case of killing two birds with one stone since Biden's surprise trip to Kyiv comes as top Chinese diplomat, Wang Yi, is due in Moscow and possibly for a meeting with Russian president, Vladimir Putin. The visit is said to be one to "discuss ideas for peace in Ukraine" but we all know that it is very much a show of support from China towards Russia on the matter.
Considering how US-China relations are suffering greatly amid the whole balloon fiasco over the past few weeks, one can definitely argue how the gesture from both sides are hardly coincidental.
And while the conflict between Ukraine and Russia is a different ordeal, the fact that the US and China are ending up on opposing sides would serve to only deepen the divide between the two at the moment.
This was definitely the perfect opportunity to highlight that contrast, I would say.