diff --git a/util/upload-instance-slot-map.py b/util/upload-instance-slot-map.py
index 8676f04636..bd5ebc1df1 100644
--- a/util/upload-instance-slot-map.py
+++ b/util/upload-instance-slot-map.py
@@ -43,26 +43,60 @@ def get_all_aws_regions(region):
     return sorted(r.get("RegionName") for r in ec2.describe_regions().get("Regions"))
 
 
-def upload(regions):
-    for region in regions:
-        bucket_name = region + "-aws-parallelcluster"
-        print(bucket_name)
-        try:
+def push_to_s3(region, aws_credentials=None):
+    bucket_name = region + "-aws-parallelcluster"
+    print(bucket_name)
+    try:
+        if aws_credentials:
+            s3 = boto3.resource(
+                "s3",
+                region_name=region,
+                aws_access_key_id=aws_credentials["AccessKeyId"],
+                aws_secret_access_key=aws_credentials["SecretAccessKey"],
+                aws_session_token=aws_credentials["SessionToken"],
+            )
+        else:
             s3 = boto3.resource("s3", region_name=region)
-            s3.meta.client.head_bucket(Bucket=bucket_name)
-        except ClientError as e:
-            # If a client error is thrown, then check that it was a 404 error.
-            # If it was a 404 error, then the bucket does not exist.
-            error_code = int(e.response["Error"]["Code"])
-            if error_code == 404:
-                print("Bucket %s does not exist", bucket_name)
-                continue
-            raise
-
-        bucket = s3.Bucket(bucket_name)
-        bucket.upload_file("instances.json", "instances/instances.json")
-        object_acl = s3.ObjectAcl(bucket_name, "instances/instances.json")
-        object_acl.put(ACL="public-read")
+        s3.meta.client.head_bucket(Bucket=bucket_name)
+    except ClientError as e:
+        # If a client error is thrown, then check that it was a 404 error.
+        # If it was a 404 error, then the bucket does not exist.
+        error_code = int(e.response["Error"]["Code"])
+        if error_code == 404:
+            print("Bucket %s does not exist", bucket_name)
+            return
+        raise
+
+    bucket = s3.Bucket(bucket_name)
+    bucket.upload_file("instances.json", "instances/instances.json")
+    object_acl = s3.ObjectAcl(bucket_name, "instances/instances.json")
+    object_acl.put(ACL="public-read")
+
+
+def upload(regions, main_region, credentials):
+    for region in regions:
+        push_to_s3(region)
+
+        if main_region == region:
+            for credential in credentials:
+                credential_region = credential[0]
+                credential_endpoint = credential[1]
+                credential_arn = credential[2]
+                credential_external_id = credential[3]
+
+                try:
+                    sts = boto3.client("sts", region_name=main_region, endpoint_url=credential_endpoint)
+                    assumed_role_object = sts.assume_role(
+                        RoleArn=credential_arn,
+                        ExternalId=credential_external_id,
+                        RoleSessionName=credential_region + "upload_instance_slot_map_sts_session",
+                    )
+                    aws_credentials = assumed_role_object["Credentials"]
+
+                    push_to_s3(credential_region, aws_credentials)
+                except ClientError:
+                    print("Warning: non authorized in region '{0}', skipping".format(credential_region))
+                    pass
 
 
 if __name__ == "__main__":
@@ -77,20 +111,35 @@ def upload(regions):
         required=False,
         default="instance-details.json",
     )
+    parser.add_argument(
+        "--credential",
+        type=str,
+        action="append",
+        help="STS credential endpoint, in the format <region>,<endpoint>,<ARN>,<externalId>. Could be specified multiple times",
+        required=False,
+    )
     args = parser.parse_args()
 
     if args.partition == "commercial":
-        region = "us-east-1"
+        main_region = "us-east-1"
     elif args.partition == "govcloud":
-        region = "us-gov-west-1"
+        main_region = "us-gov-west-1"
     elif args.partition == "china":
-        region = "cn-north-1"
+        main_region = "cn-north-1"
     else:
         print("Unsupported partition %s" % args.partition)
         sys.exit(1)
 
+    credentials = []
+    if args.credential:
+        credentials = [
+            tuple(credential_tuple.strip().split(","))
+            for credential_tuple in args.credential
+            if credential_tuple.strip()
+        ]
+
     dump_instances(args.instance_details)
 
-    regions = get_all_aws_regions(region)
+    regions = get_all_aws_regions(main_region)
 
-    upload(regions)
+    upload(regions, main_region, credentials)