President Vladimir V. Putin of Russia will not attend either, and his foreign minister, Sergey V. Lavrov, will speak instead.
In what may be another sign of France’s anger at the United States over a secret arms deal with Australia, the French president, Emmanuel Macron, has abandoned the idea of speaking at the gathering even by video. Instead he tapped his foreign minister, Jean-Yves LeDrian, to speak, which now could happen on the final day.
Iran’s new president, Ebrahim Raisi, also sent a prerecorded speech, skipping the opportunity for personal diplomacy that could help save Iran’s near-moribund nuclear agreement with major powers.
Mr. Bolsonaro will be the first head of state to address the gathering. Brazil has spoken first since the mid-1950s, and U.N. protocol officials say that the tradition began because at the time no other country’s leader was willing to take on that role. That position is now considered a coveted slot that can help set the tone of the week.
Among the other first-day speakers are the presidents of Turkey, Mexico, South Korea, Poland and the Democratic Republic of Congo.