WASHINGTON — Long called the Super Bowl of diplomacy, the opening session of the United Nations General Assembly attracts diplomats from 193 nations and dozens of heads of state. And every September, hundreds of State Department specialists in regional politics or subjects such as nuclear nonproliferation use the gathering to meet their counterparts from other nations without having to trek to the far corners of the world.

Not this year.

Under orders from Secretary of State Rex W. Tillerson, the department’s overall diplomatic delegation to the meetings that start Tuesday is expected to include about 140 officials, down from twice that number last year. Two weeks ago, the number was hovering around 80. But fierce internal complaints and questions from The New York Times led officials to make dozens of last-minute additions.

Even so, the reduced delegation means that scores of meetings traditionally held by American officials will not occur.

The Africa bureau, for instance, was initially told to slash its delegation of 30 top diplomats to 10 and then to reduce that number to just three, according to an Aug. 23 roster. The South and Central Asia bureau saw its delegation go from 30 to 10 to seven, the roster showed. A host of bureaus had their delegations eliminated entirely, including those for democracy and human rights, human trafficking, oceans and the environment, cyberissues, military issues and foreign assistance, the Aug. 23 roster showed.