put the onus on

北朝鮮の３度目の核実験を受け、国連安全保障理事会の新たな制裁決議案の文言をめぐって協議していた常任理事国の米国と中国は４日、決議案の内容に基本合意したとのことです。このタイミングを受けて、北朝鮮は休戦協定を破棄すると国営通信を通して発表しました。

Report: North Korea threatens to end armistice

North Korea threatened Tuesday to nullify the armistice agreement that ended the Korean War in 1953, citing U.S.-led international moves to impose new sanctions against it over its recent nuclear test, South Korea's Yonhap news agency reported.

The North's military said it will also cut off direct phone links with South Korea at the inter-Korean border village of Panmunjom, Yonhap said, citing North Korea's news outlet.

Pyongyang continues to make "belligerent and reckless moves that threaten the region, their neighbors and now, directly, the United States of America," U.S. Secretary of State John Kerry said in a CNN interview Tuesday.

"It's very easy for Kim Jong Un to prove his good intent here also. Just don't fire the next missile. Don't have the next test. Just say you're ready to talk," said Kerry, speaking on the last full day of his first international trip as the nation's top diplomat. Kim is North Korea's leader.

Addressing reporters later in Qatar, Kerry again put the onus on Kim to act, saying, "The American people and the world" would like to see him "take responsible actions" for peace.

"Rather than threaten to abrogate and threaten to move in some new direction, the world would be better served" if Kim tried to engage in legitimate dialogue, Kerry said.

"Our preference is not to brandish threats to each other. It's to get to the table" to negotiate, he said.

http://edition.cnn.com/2013/03/05/world/asia/north-korea-armistice-threat/index.html?hpt=hp_t2

put the onus onは「〜に責任を負わせる」という意味のイディオムです。核となるonus（重荷、責任）はラテン語に由来し、かなり堅い言い回しです（cf. onus probandi　「法律の立証責任」）。形容詞のonerousもよくみかけるので併せてチェックしておきましょう（cf. onerous contract 「有償契約」）。（UG）