[Owen]

The Vucic illness was so severe US doctors advised him not to return to Serbia. Heart problem. There was some talk of a medical assassination attempt while in the US, so he chose to leave the US and return to Serbia, despite the advice.

He went directly from airplane to a Belgrade hospital on arrival. Cancellation of Moscow trip likely but not certain. He wants to go.

[Owen]

Vucic does face a challenging election upcoming. Heart stressor.

Polling suggests he can form a coalition govt and hold power, but his party will definitely lose seats upcoming.

[Worldtraveler once upon a time]

Thanks for the added info. Looked a little further:

“The American doctors carried out all the necessary tests, and the president, contrary to their recommendation, decided to return home,” he said.

Dr Dincic said it was unrealistic to expect the president to be able to fully resume his regular activities in the coming days. The president had encountered “similar problems” three times in the past 10 years, he added. Serbian President out of hospital after cutting short US trip

One recalls that we -- meaning NATO, sort of -- bombed Serbia for a couple of months during the Clinton years (1999), which still echoes in Serbian media.