In the United States, a senior White House official with background in infrastructure and cybersecurity issues has been nominated today to head the Department of Homeland Security. <br/><br/>President Donald Trump said he was nominating Kirstjen Nielsen, a Department of Homeland Security veteran, to run the office with nearly two lakh 30 thousand employees. John Kelly, a former marine general, vacated the job when Mr Trump chose him in July as his chief of staff in a bid to bring discipline to the White House.