Basel Committee secretary-general Wayne Byres has warned that the Basel III rules are "necessary but not sufficient" for more resilient banking systems, and that supervisory capabilities must be beefed up further.In a speech released on Wednesday, Byres said that more needed to be done to overhaul the global regulatory framework. Items on the Basel Committee's agenda include a review of trading book rules, the regime governing banks' large exposures, and the treatment of securitisation within the Basel framework.He called on national authorities to actually implement the Basel III reforms in a timely and consistent manner."Implementing Basel III is essential," he said in his speech to a Financial Stability Institute conference. "But it must be accompanied by other measures and reforms so that a truly healthy banking system is secured for the future.""We need our regulatory and supervisory approaches to work in tandem, as neither is sufficient on its own."Byres compared the new Basel III rules to an exercise regime aimed at getting back into shape an unhealthy person who has been living too long on junk food and not exercising. The steps banks have already taken to bolster their capital "have had a substantial and positive effect", he said. As a result, next year's formal introduction of Basel III rules would not create disruption or financial pressure.But without bank supervisors to make banks stick to the fitness program, he said, "we will not meet our goals". So supervisory capabilities needed to be upgraded well before another crisis."Supervisors do their most important work when they are seemingly valued the least," he said.Byres was previously a senior executive at the Australian Prudential Regulation Authority, and his  comments appear to reflect the Australian regulatory family's shared perspective on the importance of supervision  to bank stability. Two weeks ago Reserve Bank of Australia head of financial stability Luci Ellis made her own argument that "diligent supervision" must accompany the Basel III rules.Byres also confirmed that the Basel Committee would announce the final form of the Liquidity Coverage Ratio "in the first part of 2013".The Committee was also looking at reviewing the current standardised approach to capital adequacy. At a minimum, he said, "we need to examine the reliance of the standardised approach on external ratings, and to see what can be done to reduce it."