The United States has blacklisted six Chinese entities it said were linked to Beijing's aerospace programs as part of its retaliation over an alleged Chinese spy balloon that traversed U.S. airspace. The economic restrictions announced Friday followed the Biden administration's pledge to consider broader efforts to address Chinese surveillance activities and will make it more difficult for the five companies and one research institute to obtain American technology exports. The move is likely to further escalate the diplomatic row between the U.S. and China sparked by the balloon, which was shot down last weekend off the Carolina coast.