ABOARD A US MILITARY AIRCRAFT (AFP) - Defence Secretary Robert Gates denied on Thursday that a US general was passed over for the military's top job due to his dissent over Afghan war strategy. When asked why General James Cartwright was not named as the next chairman of the US Joint Chiefs of Staff, Gates praised the Marine as a talented officer and said media reports were off the mark about why he was not nominated. "Some of the negative things that have been reported as influencing the decision, for example the Afghan piece, are completely wrong - had nothing to do with it whatsoever," Gates told reporters aboard his plane to Singapore. The Defence secretary was referring to widespread speculation that Cartwright - once touted as the leading candidate to become the US military's top-ranking officer - had been ruled out for the job due to friction with fellow officers over his role in a White House debate on Afghanistan. Cartwright broke ranks with military brass and Gates during deliberations on a proposed 2009 troop surge and drafted an alternative plan calling for fewer reinforcements, according to an account in Bob Woodward's book, "Obama's War." A technology-savvy officer currently serving as vice chairman, Cartwright is described in the book as President Barack Obama's "favorite general." Cartwright also faced questions about an incident involving a female subordinate officer, but the Pentagon in February cleared him of allegations that he had a romantic relationship prohibited under military rules. The probe did, however, fault the general for failing to discipline the woman after she passed out drunk on a bench in his hotel room during a work trip. The nomination choice for chairman highlighted lingering tensions between civilian aides in the White House and military leaders in the aftermath of tense debates over the Afghanistan conflict. But Gates called Cartwright "one of the finest officers I've ever worked with," and added: "I think he has made an enormous contribution. And I've enjoyed working with him for four years and consider him a friend."