The government has published its objectives for a post-Brexit trade agreement with the United States.
The government insisted the NHS would "never" be on the table in negotiations, as it said there was a commitment to "ensure high standards" and protections were maintained for consumers and workers.
The US welcomed the 184-page document, with its UK ambassador Woody Johnson tweeting: "Lots of work to do – let’s get started!"
Trade Secretary Liz Truss maintained a tough stance ahead of the negotiations, warning the UK will "strike a hard bargain" and is prepared to "walk away" if the US tries to force a breach of the government's "red lines".
The document predicts a free trade agreement (FTA) could "potentially" create an increase in trade with the US of approximately £15.3 billion in the long term.
UK negotiators would work to ensure that measures are in place to prevent hikes in medicine prices for the NHS, as the Government document said the service "will not be on the table".
"The NHS is not, and never will be, for sale to the private sector, whether overseas or domestic," the document said.
The Government acknowledged public concerns about US meat, particularly chlorine-washed chicken and hormone-fed beef.
"Throughout the agreement, ensure high standards and protections for UK consumers and workers and build on our existing international obligations," the document said.
"This will include not compromising on our high environmental protection, animal welfare and food standards."
Ahead of the document being published, a consultation was held to address unease in the UK around the potential trade deal.
The document said concerns were raised around US food standards in a number of areas, including use of genetically modified organisms (GMOs), "hormone-fed or injected beef", over-use of pesticides, "chlorine-washed chicken" and levels of preservatives or additives.
"For both food and product standards, respondents also noted potential opportunities to reduce UK-US trade barriers by harmonising standards/levels of protection or through mutual recognition, as long as UK standards are maintained and there is continued alignment with the EU."
Prime Minister Boris Johnson has pledged to "drive a hard bargain to boost British industry" in the talks, which will take place alongside negotiations with the EU.
Talks in Brussels were to get under way on Monday, when the Prime Minister's Europe adviser David Frost was to meet the team led by EU chief negotiator Michel Barnier.
Downing Street has been urged by trade union leaders not to "cosy up" to US President Donald Trump during the talks, with the PM being asked to block any US manoeuvring to lower food standards.
Ministers have repeatedly faced demands to rule out chlorinated chicken and hormone-treated beef being imported from the US in any deal, with animal welfare and environmental concerns raised.
Crawford Falconer, the Department for International Trade's chief trade negotiation adviser, will oversee talks with Washington on the UK side.Negotiating rounds will alternate between the UK and US.