ANKARA (Reuters) - The United States penalising Turkey for its purchase of Russian S-400 missile defence systems would be “so counter-productive” and would harm Turkish-U.S. ties, presidential spokesman Ibrahim Kalin said on Wednesday. Kalin said Turkey believed it can have a good, positive agenda with the administration of U.S. President-elect Joe Biden. He was speaking via video conference in a German Marshall Fund of the United States event.