The Bush administration has accused senior U.N. officials of "manipulating the truth" by suggesting that the United States is backsliding on commitments made over the past five years to increase foreign assistance to the world's poor.

Ric Grenell, the spokesman for the U.S. mission to the United Nations, wrote in an e-mail to the world body's top spokesmen that a recent U.N. press statement indicating that President Bush had endorsed a list of aid targets, known as the Millennium Development Goals (MDGs), reflected a "bias" against the United States that he said was a "deep cause for concern."

The remarks came one week after John R. Bolton, the U.S. ambassador to the United Nations, told U.N. delegates for the first time in writing that the Bush administration never agreed to support the goals, which call for increased funding to drastically reduce poverty, halt the spread of HIV/AIDS and eradicate a host of deadly diseases by 2015.

But Bolton and other administration officials have expressed support for the 2000 Millennium Declaration, a document that included the specific goals. And the United States objects to an annex to the goals -- known as indicators -- that calls on countries to set aside 0.7 percent of their gross national product to finance the efforts.

The Bush administration's position has fed a worsening dispute over the obligation of rich states to increase development aid, a disagreement that threatens to dominate the Sept. 14 summit of world leaders on poverty and U.N. reform. It also has hardened opposition by poor countries, represented by the Group of 77 developing nations, to U.S.-backed proposals to establish independent oversight of U.N. spending, restrict the spread of the world's deadliest weapons and create a new human rights council that excludes membership by human rights abusers.

The administration says it has doubled U.S. aid to Africa, to $3.2 billion last year, and remains committed to increasing foreign assistance to poor countries that have demonstrated a capacity to spend it wisely. But it insists that it has always opposed funding to meet abstract numerical targets.

Bush unveiled the centerpiece of his development policy, the Millennium Challenge Account, at a U.N. summit on development in Monterrey, Mexico, in 2002. The administration pledged to spend $1.7 billion in 2004, $3.3 billion in 2005 and $5 billion per year thereafter to help select countries. But the program has been plagued by delays, and the United States has reached agreements with only three countries. The largest deal is to spend $215 million in Honduras over five years.

The United Nations, meanwhile, has said that Bush and other leaders of industrial powers endorsed the Millennium Development Goals at the Group of 8 summit in Evian, France, in 2003. It also noted that Bush endorsed the Monterrey Consensus, an agreement that urged wealthy countries to "make concrete efforts towards the target of 0.7 percent of gross national product" in foreign assistance.

A senior administration official said that U.S. negotiators made it clear at the time that the administration opposed the idea of committing to a numerical target but did not want to block language supported by many of its allies.

Jeffrey Sachs, a Columbia University economist who is advising U.N. Secretary General Kofi Annan on development, charged Wednesday that Bolton's assertion that the United States never backed the Millennium Development Goals was "without ground." He said the goals are drawn "straight from the Millennium Declaration" and that the administration is simply trying to "wriggle out" of its commitments.

Annan said he was still hopeful that the administration would drop its opposition to the goals, which U.N. officials assert have galvanized international support for the fight against poverty.

"I'm not sure that the U.S. is going to insist on that," Annan told reporters Wednesday. "I think they've made their point, but I'm not sure the other member states would want to see the Millennium Development Goals dropped or, the worse, expunged from the document."

U.N. Ambassador John R. Bolton signals a desire to speak at a meeting on global planning.