U.S. President Barack Obama has been hit with an unusual rebuke from a British government official for his alleged failure to deal with the issues of global warming and climate change.

Greg Barker, MP, Minister of State for Energy and Climate Change, told a British conference that Obama had not lived up to the promises he had made on tackling climate change and global warming.

“We need Obama not just to make speeches, but he needs to put his money where his mouth is and invest political capital domestically,” Barker said.

“Unless the U.S. joins with the rest of the world and shows real leadership on this ‘green’ agenda, we are not going to get a global agreement.”

He added: “[Obama] came to office with a huge amount of goodwill and huge degree of hope invested in the pledges that he made in the early days of his presidency to address the climate challenge. There hasn’t, I believe, been a concerted political effort by the administration at a time when there was an opportunity potentially to push the agenda forward. Not acting then proved to be a huge loss.”

The climate minister also vented against Obama on Twitter, where he wrote: “Obama: Climate change ‘cannot be denied. We see it in stronger fires, devastating floods, Pacific islands confronting rising seas.’ THEN ACT!”

The comments come ahead of a United Nations climate treaty conference in Durban, South Africa next week.

Environmentalists have been as equally angered by the failure of other world leaders to unanimously agree to a reduction in global greenhouse gases.

The greenhouse gas targets agreed to at the 1997 Kyoto Protocol expire at the end of next year – with a number of nations apparently refusing to agree to a new pact of reducing greenhouse gas emissions.

Indeed, some countries believe such regulations will undercut their economic recoveries.

Obama said that the US agreed to reduce such emissions by 17 percent over the next fifteen years – however, the US Congress has blocked legislation on the deal.

The UN’s weather agency, the World Meteorological Organization (WMO), just released a report stating that the emission of greenhouse gases has spiraled over the past decade to levels beyond the worst-case scenarios that experts had forecast.

WMO indicated that carbon dioxide levels rose by 2.3 parts per million (ppm) between 2009 and 2010 -- a faster rate than the average of 2.0 ppm recorded over the past decade.

Michel Jarraud, secretary-general of the WMO, said: “Even if we managed to halt our greenhouse gas emissions today -- and this is far from the case -- they would continue to linger in the atmosphere for decades to come and so continue to affect the delicate balance of our living planet and our climate.”

Meanwhile, officials of the British government say they are committed to slashing emissions.

Baroness Stowell of Beeston, an energy minister said Westminster is “committed to being the greenest government ever”.