rke kubernetes cluster context deadline exceeded while pulling image

I have a kuberenetes cluster that I set up with RKE (version 1.3.14).

When I am trying to create some pods (that pull docker images from digitalOcean container registry) I recieve the following error:

Failed to pull image "registry.digitalocean.com/........": rpc error: code = Unknown desc = context deadline exceeded

I am not able to create pods that their image pull process takes more than 2 minutes. I added the following to my cluster.yml configuration and ran rke up again to update the cluster:

services:
  kubelet:
    extra_args:
      runtime-request-timeout: '1h'

But it seems to have no effect and I get the same error.

Thanks,