LONDON (Reuters) -Britain and the United States will sign a deal to work together on boosting nuclear power during U.S. President Donald Trump's state visit this week, the British government said, helping secure investment to fund new plants. Britain's government has launched a major push to expand nuclear power in recent months, pledging to invest 14 billion pounds ($19 billion) in a new plant at Sizewell C and advancing plans for a Rolls-Royce unit to build the country's first small modular reactors (SMR). Trump arrives in Britain for a two-day visit on Tuesday, during which he and Prime Minister Keir Starmer will announce the nuclear power tie-up.