Former British foreign secretary David Miliband has said Kevin Rudd “undoubtedly had the qualification” to be a candidate for the United Nations secretary-general post.

Miliband said Rudd is regarded as a “heavyweight” in the international environment.

“I think he is seen as someone with a genuine global view, at a time when the global community is struggling in areas such as security, economics, and the humanitarian refugee crisis,” Miliband told The Conversation.

Rudd was often seen as ahead of his time in understanding, for example, the rise of China and issues of multilateralism, he said.

Miliband said the race and selection process for the UN job was more open than ever before and to have had Rudd’s perspectives heard in the debate would have been valuable.

Last week the government refused to nominate Rudd, thus preventing him being a candidate. Malcolm Turnbull told the former prime minister and foreign minister that he was unsuited for the position.

After cabinet considered Rudd’s candidature, the official line was that the decision was left to Turnbull.

But disputing it was a “captain’s pick”, Deputy Prime Minister Barnaby Joyce said at the weekend there was a majority in cabinet against the Rudd nomination. This prompted leaks that cabinet was marginally in favour of the nomination – which was strongly supported by Foreign Minister Julie Bishop – before Turnbull and Joyce took over the matter, with Joyce saying he would back whatever Turnbull decided.

Miliband, who was the Labour government’s foreign secretary between 2007 and 2010, is CEO of the International Rescue Committee, a non-government humanitarian organisation that gives assistance in war-torn countries. He stressed he was speaking in his private capacity, not on behalf of the committee.

Miliband, now based in New York, said the assumption in diplomatic circles and among policy watchers had been that Rudd would be a candidate for the UN job. Rudd’s record and ideas meant that no-one was expressing any surprise at that.

In conversations about the secretary-generalship “no-one ever said to me that he was unqualified to be a candidate, that he was not worthy of consideration.

"There will undoubtedly be a view among those who want reform of the international system that it would be an enormous pity if his ideas for reform fell by the wayside because his candidacy fell by the wayside,” Miliband said.