World leaders pledged $1.1 trillion in loans and guarantees to struggling countries and agreed Thursday to crack down on tax havens and hedge funds — but failed to reach sweeping accord on more stimulus spending to attack the global economic decline.

At the end of a highly anticipated one-day gathering, leaders of the Group of 20 nations said they would upgrade an existing financial forum to serve as an early warning monitor to flag problems in the global financial system.

They did not, however, satisfy U.S. and British calls for new stimulus measures. Nor did European politicians get their goal of a global financial superregulator.

The leaders did bridge several gaps between the United States and some European nations over how far to regulate the market and how to curb the excesses that sparked the global economic crisis.

President Barack Obama, in his first major venture into international diplomacy, failed to get U.S. trading partners to spend more money on job-creating stimulus programs, as the U.S. and Britain have done. The proposal was opposed strongly by France and Germany.

However, it had become clear long before the gathering began that there was little support for more such stimulus spending outside the U.S. and Britain.