GlaxoSmithKline (GSK) is set to cut hundreds of jobs in the US as part of a new cost-cutting strategy.In October, the British drug-maker unveiled plans aimed at saving £1bn in annual costs over the next three years and it is expected to cut staff jobs in its biggest market.According to sources quoted by Reuters, the company's head of North American pharmaceuticals Deirdre Connelly will brief GSK's employees on Wednesday."Each business unit is currently deciding how to respond to this challenge. When we do have proposals, we will first share those with our employees," a spokesman for the firm said on Sunday.The group has seen sales of respiratory drugs fall in the US, amid stronger competition and a tougher stance from US health regulators on drug-makers that choose to cut prices for older products.