Tension is simmering between U.S. and Ethiopian officials as investigators prepare to release in the coming days an interim report about the Boeing Co. 737 MAX jetliner that nose-dived after takeoff from Addis Ababa on March 10, according to people from both countries.

U.S. investigators, according to people familiar with their thinking, have privately complained that Ethiopian authorities have been slow to provide data retrieved from the black-box recorders of Ethiopian Airlines Flight 302, which went down minutes into a flight to Nairobi, killing all 157 people on board.

American air-safety officials also have described what they view as an aloof attitude among the Ethiopians toward other investigators and say the Ethiopians have provided often limited access to relevant crash information, these people said.

A spokesman for the Ethiopian transport minister didn’t respond to requests for comment Sunday. Ethiopians involved in the probe, for their part, have chafed at what they see as American efforts to exert control over the preliminary report, according to other people familiar with the investigation.

The behind-the-scenes maneuvering, according to people from both countries, has impeded but not prevented the international investigators from working together.