Amazon on Tuesday said it will raise its minimum wage to $15 in the United States, a response to mounting pressure over its wages and treatment of its warehouse workers.

In its announcement Tuesday, Amazon said it would lobby for an increase in the federal minimum wage, which has been stuck at $7.25 for a decade. The rise for London workers will be 28%.

He said Amazon had "listened" to its critics, "thought hard about what we wanted to do, and decided we want to lead".

The new wage will apply to full-time, part-time, seasonal and temporary workers. And some companies have responded to the public pressure.

In addition to committing to higher minimum pay, Amazon says it will "work with policymakers in Washington, D.C., to advocate for a higher federal minimum wage". And in January Walmart raised its starting wages to $11 per hour.

Amazon has previously contested some of Sanders' claims, saying its full-time warehouse workers already make $15 when stock and bonuses are included. Mr Bezos said he encouraged the company's competitors to increase their own minimum wages. Many business groups and conservative argue $15 an hour is too high, especially in lower cost-of-living places outside urban centers.

Neil Saunders, managing director of GlobalData Retail, said Tuesday that while Amazon's wage hike is a politically savvy move, it's also a change made out of economic necessity.

Workers have been protesting against fast food chains like McDonald's Corp and demanding wage increases since 2012 but conditions at Amazon's warehouses, distribution centers and for its couriers have been drawing media attention and criticism for some time.

Amazon also raised its minimum wage in Britain to 10.50 pounds ($13.59) an hour for all employees in the London area and 9.50 pounds an hour for staff in all other parts of the country, effective from November 1.