AMSTERDAM (AP) — The failure of a climate bill in the U.S. Senate is likely to weigh heavily on international negotiations that begin Monday on a new agreement to control global warming.

The decision to strike the bill from the Senate's immediate agenda has deepened the distrust among poor countries about the intentions of United States and other industrial countries to cut greenhouse gas emissions that power their wealthy economies but risk causing the Earth to dangerously overheat, say climate activists.

A split between rich and poor nations has characterized the talks since they began 2½ years ago, but it widened after the disappointment of the Copenhagen climate summit last December that fell short of any binding agreement and produced only a brief document of political intentions.

The withdrawal of the bill to cap U.S. emissions of carbon dioxide, the most prominent gas blamed for global warming, "plays into the same old fault lines," said Kelly Dent, of Oxfam International. It has let down developing countries that had looked to President Barack Obama's administration to seize the leadership in climate negotiations, she said Sunday from Bonn, Germany.

Delegations from most of the 194 participating nations begin a five-day negotiating session in Bonn on Monday that is one of the last meetings before another decisive conference convenes at the end of the year in Cancun, Mexico. One more weeklong round of talks is scheduled for October in China.

The two keys to any agreement are commitments by rich countries to cut emissions and their pledges to fund poor countries' actions to adapt to climate changes affecting agriculture and the frequency of extreme weather events like floods and drought.

So far, Washington has not backed away from its promise at Copenhagen to reduce emissions 17 percent below 2005 levels over the next 10 years. But even that pledge, made more doubtful now by legislative inertia, has been roundly criticized as inadequate.

Christiana Figueres, presiding over the talks for the first time since becoming executive secretary of the U.N. Framework Convention on Climate Change a month ago, says the industrial countries must lift their emissions reduction pledges if they hope to limit global warming to manageable levels this century.

Pledges given so far amount to reductions of 12 to 19 percent below 1990 levels, she told reporters last week. U.N. scientists have said the rich countries must slash emissions by 25 to 40 percent by 2020. Because carbon dioxide accumulates in the atmosphere, scientists say it is crucial to act quickly to reach a peak in global emissions.

The U.N. negotiations aim to reach a deal to succeed the 1997 Kyoto Protocol, which called on a list of industrial countries to cut emissions by a total 5 percent by 2012 as measured against 1990.

The United States rejected Kyoto, partly because it made no demands on rapidly developing countries like China, which now produces more much heat-trapping gases than any other country.

Developing countries now say they are willing to take steps to control emissions, but that they must be given space to build their economies. Although China is the largest carbon polluter and India is rapidly catching up, both countries lag far behind the industrial countries in emissions per person and still have huge populations mired in poverty.

Shifting to a lower gear, Figueres says it would be a mistake to seek an overarching package deal in Cancun, which she said would "ignore the need to continue innovating" to combat global warming.

Instead, delegates should focus on a few essentials they can build on later. One is a practical plan for raising and distributing $30 billion over the next three years to poor countries, as pledged at Copenhagen, she said.

After a meeting last week in Rio de Janeiro, the environment ministers of Brazil, China, India and South Africa — an increasingly important negotiating bloc known as the BASIC countries — said "fast-start finance will be the key for an effective result" in Cancun.

Financing must be new, rather than repackaged development aid, and should be given as grants, the four countries said in a joint statement.