He said Barclays would spend on information technology to improve risk management, retail services and operational flexibility and to cut costs.
Technology offered 'huge opportunities' to provide greater value to customers at lower costs, However, it also posed a threat as it enabled new entrants to compete in the financial services market, by using increasingly effective delivery and distribution channels.
Mr Buxton was speaking in Kuwait, at an international conference on Gulf banking.
'I doubt whether any international bank can face the future with any confidence at all unless its information technology spending is relatively high,' he said. Barclays has already spent pounds 800m on technology around the world.
Mr Buxton also said the time had come to consider raising minimum capital ratios. Banks should keep high capital ratios and regulators might have set minimum capital requirements too low.
Barclays and TSB have denied press reports, however, that they were planning imminent buy-backs of shares to return a total of pounds 2bn of cash to shareholders.
Barclays has been reviewing its capital needs since the spring. In August it offered to buy back several hundred million dollars' worth of subordinated debt. A spokesman said further moves were possible, but reports were speculative.
A TSB spokesman said it had no immediate plans, although it has shareholder approval for a buy-back of up to 15 per cent, or nearly pounds 500m.
Both banks have core 'tier 1' capital-to-asset ratios well above the 4 per cent minimum.