PM embarks on busy four days

Prime Minister John Key's whirlwind New York tour was to begin in earnest about 3.15am today (NZ time), with a United Nations General Assembly summit on climate change, and a meeting with Secretary-General Ban Ki Moon.

The next four days will include meetings with his Israeli counterpart, Benjamin Netanyahu, Nato secretary-general Anders Fogh Rasmussen and a brief meeting with President Barack Obama.

He will hold a press conference with former Prime Minister Helen Clark - now UN number three - tomorrow morning.

His tour concludes on Saturday with a meeting with Palestinian President Mahmoud Abbas, and a speech to the United Nations General Assembly.

But his schedule is not all work - at least not in the traditional sense. He appears tomorrow on the Late Show with David Letterman.

His fellow guests will include alternative rock band Snow Patrol, and Scottish/American comedian Craig Fergusson, once a member of punk band The Bastards from Hell.

Mr Key's appearance on the Late Show will be the third by a national leader, or former head of state, this week.

President Obama appeared on the show on Monday to try to calm the debate raging in the United States over his political agenda.

He also spoke about the war in Afghanistan, admitting Americans were growing weary of the conflict but praising the troops for continue to fight "heroically".

Former President Bill Clinton was scheduled to appear on the show today.

Mr Key is expected to deliver a Top 10 list, the content of which is a secret until delivery.