WASHINGTON, Aug 31 (Reuters) - The U.S. State Department has raised its travel advisory alert for Canada to a "level  3 – reconsider travel" status amid the ongoing COVID-19 pandemic, it said in a statement on Tuesday. The department, along with the U.S. Centers for Disease Control and Prevention, warned on Monday against travel to Switzerland, among other countries because of rising cases of the novel coronavirus. read more The CDC also raised its COVID-19 travel warning to "level 4: very high" for the U.S. island territories of Puerto Rico and Guam. Puerto Rico said on Tuesday it would close some private businesses and prohibit alcohol sales after midnight effective Thursday. The Caribbean island also said it was requiring mandatory use of masks in open places where 50 people or more are gathered and prohibiting elective surgeries, subject to medical criteria, which require the use of post-operative intensive care units.