U.S. President Barack Obama must have been under pressure.

He made an unusual slip of tongue, calling South Korean President Park Geun-hye “Madame Prime Minister” during trilateral talks with the leaders of South Korea and Japan.

Obama brought the leaders of the United States’ key Asian allies to the same table on the sidelines of the Nuclear Security Summit in The Hague, Netherlands, Tuesday.

Obama was expressing his appreciation to the two leaders for attending the meeting. But the U.S. president, who is usually known as an eloquent speaker, mistakenly said while turning his head to Park: “Thank you very much again to Madame Prime Minister … uh … Madame President and Prime Minister Abe.”

Reports say Obama referring to Park as P.M. shows that he was intimidated by the awkward mood that prevailed throughout the three-way meeting.

(christory@heraldcorp.com)