Sept 17 (Reuters) - GSK said on Wednesday it

plans to invest $30 billion in research and development and

supply chain infrastructure in the United States over the next

five years, after U.S. President Donald Trump arrived in Britain

for an unprecedented second state visit to seal investment

deals.

The company said its new facilities will "bridge R&D and

manufacturing across both the U.S. and UK, strengthening the two

countries' leadership in life sciences".

London-based GSK said the investment includes $1.2 billion

for the construction of a new factory at Upper Merion,

Pennsylvania, to produce new medicines for respiratory disease

and cancer, with construction planned to commence in 2026.

It will also invest in AI and advanced digital technology

capabilities across GSK's existing five manufacturing sites in

the country, along with new drug substance manufacturing

capabilities and improved device and auto-injector assembly.

GSK is the latest drugmaker to scale up its U.S. footprint

as Trump threatens to impose import tariffs on the industry and

seeks to boost domestic manufacturing. The sector has

historically been spared from trade disputes.

"This landmark investment will create tens of thousands of

American jobs and ensure that critical medicines and

technologies are developed and manufactured right here on U.S.

soil-where they belong," U.S. Commerce Secretary Howard Lutnick

said.

The $30 billion investment will help bolster R&D and

clinical trial activity, and the U.S. is expected to rank first

for the number of studies, sites and clinical trials

participants conducted by GSK over the next five years,

according to the company.

However, it did not comment on whether the $30 billion

included funds that had already been earmarked for the U.S.

business. But pharma industry sources have told Reuters a number

of firms that have announced large U.S investments under Trump

have included projects or sites already in the works in order to

give a large headline figure.

GSK said it has committed about $2 billion to U.S.

manufacturing over the past year, and that the investments will

add hundreds of skilled jobs, on top of construction roles, and

build on its roughly 15,000 strong U.S. workforce.

The U.S. accounted for nearly half of GSK's revenue last

year.