LONDON (AFP) - Britains Tony Blair may have swung behind US calls for regime change in Iraq after meeting President George W Bush at his Texas ranch in 2002, a top diplomat told an inquiry into the war on Thursday. Christopher Meyer, then Britains ambassador to Washington, said Blairs line seemed to harden following talks at the Crawford ranch in April 2002, much of which were held in private with no advisors present. He also detailed the warm personal relationship between the British prime minister and US president, saying Bush could talk to Blair but saw other world leaders as being like creatures from outer space. Blair was Bushs closest ally in the US-led invasion of Iraq in 2003, carried out without UN Security Council approval. He resigned in 2007, partly due to the wars unpopularity. The probe heard that toppling Iraqi president Saddam Hussein was not an early priority for Bush, but on the day of the September 11, 2001 attacks by Osama bin Ladens Al-Qaeda network, the US raised questions about possible links to him. Meyer, ambassador to the United States from 1997 to 2003, said he was not entirely clear what degree of convergence was, if you like, signed in blood at the Crawford ranch. But the day afterwards, Blair made a speech in which he publicly mentioned regime change for the first time. Our monitoring desk adds: Former British prime minister Tony Blair received intelligence that Saddam Husseins weapons of mass destruction had been 'dismantled 10 days before Britain invaded Iraq, the Chilcot inquiry has been told. The British Foreign Office did not believe Iraq had nuclear missiles, but Mr Blair told Parliament Saddam was still a threat to the Middle East with chemical and biological weapons that could be launched at 45 minutes notice. But Sir William Ehrman, the director of international security at the Foreign Office from 2000 to 2002, told the inquiry into the Iraq war: 'We were getting, in the very final days before military action, some [intelligence] on chemical and biological weapons that they were dismantled and [Saddam] might not have the munitions to deliver it. 'On March 10 [2003] we got a report saying the chemical weapons might have remained disassembled and that Saddam hadnt yet ordered their reassembly, and he might lack warheads capable of effective dispersal of agents. Despite the information, coalition forces invaded Iraq on March 20, 2003. The issue of Iraqs ability to produce or use weapons of mass destruction is central to the inquiry, which must determine whether Mr Blair misled Parliament over reasons for going to war. Tim Dowse, the head of counter-proliferation at the Foreign Office between 2001 and 2003, told the inquiry Iraq had not been top of the list for nations causing concern about the spread of weapons of mass destruction in the two years before the invasion. Mr Dowse said Iran, North Korea and Libya had caused far greater alarm than Saddams regime. He said that when he came to the job in 2001, both Libya and Iran had been placed ahead of Iraq. And while Saddam had supported Palestinian terrorist groups, the assessments worked on by his officials described the regimes contacts with al-Qaeda as quite sporadic. After 9/11, we concluded Iraq actually stepped further back. They did not want to be associated with al-Qaeda. They werent natural allies, he said. The Foreign Office ranked Iraq only the fourth most dangerous rogue state trying to develop WMD in 2001. Sanctions made it virtually impossible for Saddam to restart his nuclear program, the inquiry heard, and even without sanctions it would likely have taken five years for it to build a nuclear weapon. The hearing continues.