BRUSSELS — A Pentagon proposal to greatly reduce American forces in West Africa faced criticism from allies on Tuesday, with French officials arguing that removing United States intelligence assets in the region could stymie the fight against extremist groups.

American officials said they were proceeding nonetheless.

While no final decision has been made on how many troops will be transferred from Africa and the Middle East as the Pentagon refocuses its priorities to confront “great powers” like Russia and China, America’s top military officer said the United States needed to shift its forces to better counter China in particular.

Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, acknowledged that the proposal was “causing some anxiety.” But he said that the United States needed to seriously re-examine its military footprint in Africa, and the Middle East and Latin America after that, given the heightened focus on China.

General Milley’s comments came ahead of a NATO military chiefs’ meeting in Brussels, where he also sought to lay out the United States’ rationale for killing Iran’s top military commander, Maj. Gen. Qassim Suleimani this month. The killing of General Suleimani, who was the head of Iran’s Islamic Revolutionary Guards Corps’ Quds Force, has raised questions from America’s military allies about whether commanders of sovereign countries are now fair game for drone strikes.