[Python] Invoke an AWS lambda across regions

I have three lambda functions: boss, worker1, worker2. When using boto3.client.invoke I am able to call worker1 from boss. These two are in the same region.
worker2 is in a separate region. When attempting to call worker2 from boss the following error returns:
"An error occurred (ResourceNotFoundException) when calling the Invoke operation: Functions from 'us-east-1' are not reachable in this region ('us-west-2')" . boss has an execution role with the following permission:

{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"lambda:InvokeFunction"
],
"Effect": "Allow",
"Resource": "arn:aws:lambda:*:*:*"
}
]
}


Please help clarify how permissions need to be conveyed for this to work. Thanks

Edit: master and worker1 are in us-west-2 and worker1 is in us-east-1.
Here is the code used to invoke worker from master:

def lambda_handler(event, context):
function_name = "arn:aws:lambda:us-east-1-...:function:worker_2"
lambda_client = boto3.client('lambda')
payload = json.dumps({"body-json": "payload string")
response = lambda_client.invoke(
FunctionName = function_name,
Payload = payload
)
response_payload = response['Payload'].read()
response_arr = json.loads(response_payload)
return response_arr['answer']

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