The United States has spent $500 million on relief and reconstruction projects in Afghanistan since last October.

Speaking at a Pentagon briefing Tuesday, Defense Secretary Donald Rumsfeld said the U.S. army is overseeing infrastructure projects in 10 regions of Afghanistan. The secretary said troops are digging wells, building schools and hospitals and repairing roads and bridges.

He said the improvement in daily life there is evidenced by the return of many Afghan refugees.

The defense secretary also said more than one billion additional dollars have been designated for rebuilding Afghanistan over the next four years.

In addition to the United States, other countries also have been sending humanitarian aid to Afghanistan. Jordan, Spain and Korea have built hospitals and other countries have contributed to landmine clearance.