The United Nations' Mideast envoy has given a rare upbeat assessment in the Gaza Strip, saying that postwar reconstruction is speeding up.

Thousands of homes were destroyed or damaged in the 50 days of fighting between Israel and the Hamas militant group last summer. The reconstruction of hundreds of houses started last month with help from Qatar, which has donated millions of dollars to rebuild 1,000 housing units.

U.N. envoy Nikolay Mladenov said in Gaza City on Thursday that reconstruction has "visibly accelerated" over the past two months.

Construction materials are shipped into Gaza from Israel through a U.N.-supervised program that ensures the goods are not diverted to Hamas.

Mladenov warned, however, that faster construction would require the internationally recognized Palestinian Authority to take back control of Hamas-ruled Gaza.