Prime Minister John Key used a meeting with United States officials to personally press for a mid-2010 visit to the White House, worried that the issue "potentially could turn into a political embarrassment for him".

A secret cable between Wellington and New Zealand obtained by Fairfax Australia from Wikileaks reveal the request was made during a meeting with US Ambassador Dave Huebner and "a Washington visitor" in February amid widespread expectations of a White House visit in March. The visit never happened.

» View the WikiLeaks cables here

Mr Key's personal pitch is noted in the cable as a measure of the depth of New Zealand's concern about the issue; it was the first time he had personally raised the issue himself, preferring previously to leave the discussions to Foreign Affairs Minister Murray McCully and his officials.

The cable hints at some awkwardness in the discussions, referring at one point to the "circuitous" manner in which Mr Key raised the issue.

"He claimed that he was not merely focused on that aspect of US-NZ relations, and understood that President Obama was busy."

The cable tallies with private briefings to journalists by senior National sources at the time; they were expecting Mr Key to make a separate visit to Washington sometime in the first half of the year.

That appears to have been a factor in rising embarrassment that the trip had not come off, with Mr Key implying that he had been led astray by the Americans.

"He recounted the conversations at APEC which led him to believe he had a firm invitation from POTUS [the President of the United States] for a separate bilateral visit in the first half of 2010," the cable states.

"Key said the exchanges resulted in him briefing the press in a certain way about the 'invitation', which he said he would not have done if he had thought the offer were actually more casual and indefinite. Expectations in New Zealand were set, Key said, and the matter potentially could turn into a political embarrassment for him. Key noted that his June schedule was 'still empty'."

The cable concludes: " The manner in which PM Key pitched the bilateral visit indicated to the Ambassador that nailing down a June visit is of intense importance to Key."

It is not clear why the visit did not come off, and an earlier cable refers to an invitation to Mr Key for a bilateral meeting with US President Barack Obama in March.

Asked about that trip last week Mr Key's office said it had not worked out because of President Obama's busy diary.

But it appears that there was also some gamesmanship underway; the latest cable refers to Mr Key explaining to the Americans why a proposed bilateral with President Obama on the fringes of the nuclear security summit "will not work".

This also tallies with briefings to media by senior National sources at the time; they saw huge symbolism in a White House visit and the bilateral meeting offered with President Obama would probably have been elsewhere.

While Prime Minister Helen Clark visited the White House twice, it has been decades since a National leader did so.

The cable also refers to discussions about the US review of military ties between the two countries which effectively dropped the decades-old ban on military training and exercises imposed after the Anzus bust-up over New Zealand's anti-nuclear legislation.

It reveals that Mr Key over ruled the Ministry of Foreign Affairs and Trade on the need for a media strategy in relation to the military review, saying he was confident that he could handle any questions.

Earlier cables have revealed that both countries planned to keep the military review secret.