A North Korean newsreader announces the country is ready to launch a merciless attack against the United States, potentially involving a "diversified nuclear strike."<br/> <br />The Thursday declaration comes as the North barred staff from the South from entering a joint-industrial park for a second day, causing tensions between the two to climb sharply.<br/> <br />Businesses operating in the Kaesong industrial zone held a news conference, claiming the North has demanded South Korean operations pull out by April.<br/> <br />South officials contend the report is distorted, despite the fact the North has threatened to shut the park, which generates $2 billion a year in trade .<br/> <br />There are 828 South Korean workers still in the zone.<br/> <br />But just 222 had indicated they wanted to return to South Korea on Thursday, with the rest trying to keep their factories running.<br/> <br />Should a conflict spark they risk to become potential hostages.<br/> <br />Japanese officials have condemned what it sees as the Nort
