Retail sales in the world's biggest economy rose at the fastest rate for five months in February, continuing the recent trend of upbeat economic data.
London's leading shares index closed 63.2 points higher at 5955.61, while the Dow Jones Industrial Average was up 0.9% at the time of the UK close.
The latest rally came amid optimism that the US Federal Reserve will signal an improvement in the economic outlook.
Despite the better sentiment, investors were hoping the Fed will stop short of ruling out further monetary easing.
UK trade figures, revealing a strong boost to exports in January, strengthened the pound which rose to 1.57 against the US dollar and 1.19 against the euro.
Insurers Standard Life and Preudential were on the front foot after their full-year results got a positive response from investors.
Edinburgh-based Standard bettered expectations with a 28% rise in profits to £544 million, despite a 6% drop in the UK, meaning its shares lifted by as much as 2% early on before closing 0.9p higher at 238.5p.
Standard said rising life expectancy and Government changes to increase the proportion of the population saving for retirement meant the UK represented an "exciting market".
Prudential's shares were up 35p or 5% to 763p, after its Asian business drove a 33% rise in pre-tax profits to £1.94 billion.
Its Asian profits rose 32% to £709m and have now nearly trebled in the past three years, driven by the booming middle class' appetite for life insurance and other savings and protection products. That compares with profits growth of just 1% to £683m in the UK.
Among other financial stocks, HSBC rose 16.3p to 572.4p, while Barclays was up 3.7p at 239.6p.
Taxpayer backed Lloyds and RBS were also higher after they revealed plans to cut 1300 and 464 jobs respectively. Lloyds improved 0.9p to 34.6p and RBS lifted 0.4p to 25.8p.
The biggest faller was Chilean miner Antofagasta amid disappointment at the size of its dividend in full-year results. Shares were 29p lower at 1241p.
There was also a fall of 6p to 283.5p for security firm G4S, offsetting recent gains, as full-year profits fell 17% to £279m.
Car dealership Inchcape rose 10% amid better-than-expected underlying profits of £227.7m, despite challenging conditions in the UK. Its performance has been driven by strong trading in Asia and emerging markets.