North Korea reportedly extended an offer to Israel in 1999 to nix its agreements to sell missile technology to Iran and other enemy states that posed a threat to the Jewish state at the time – if Israel paid Pyongyang $1 billion in cash.

According to a report in the Wall Street Journal published Sunday, Israel did not take the offer. Instead, Jerusalem offered food aid and the talks ended without an agreement.

The alleged and failed extortion attempt took place during an exchange between North Korea’s envoy to Sweden and his Israeli counterpart while the pair met in a café in Stockholm, the Journal reported.

The account of this covert exchange has been detailed in a memoir penned by the translator at the meeting, a former senior North Korea diplomat named Thae Yong Ho, who has defected to South Korea two years ago.

The Israeli government refused request for comment. Iran has denied that it had talks with North Korea on nuclear technology, and its embassy in Seoul also did not respond to a request for comment.

The Journal said that it could not reach the two ambassadors who are reported to have held the talks almost two decades ago- the former Israeli envoy to Sweden, Gideon Ben Ami, and the North Korean ambassador, Son Mu Sin.

Last week, Ben Ami said in a televised interview that he held three meetings with North Korea officials in 1999, but did not disclose any request for payment by North Korea.

North Korea’s Son Mu Sin currently serves in the foreign ministry in Pynogyang, according to an official at the North Korean delegation to UNESCO.

The Journal claims that declassified State Department documents from that time attest to the fact that the U.S. and North Korea held talks concerning Pyongyang’s missile exports around the time Yong Ho says he and his boss were in touch with Israeli officials.

This report comes against the backdrop of an escalating dialogue between the U.S. and North Korea over the latter’s nuclear weapons.

Over the weekend, U.S. Secretary of State Mike Pompeo held tense talks with Pynogyang in which North Korea accused Donald Trump’s administration of making ‘gangster-like’ unilateral demands and violating the June 12 summit between Trump and Kim Jong Un.