North Korea's foreign minister is scheduled to visit Iran on August 7, as both countries deal with stepped up political and financial pressure from the United States over their nuclear programs.

Ri Yong Ho is set to make the trip following his attendance at the ASEAN summit in Singapore, where he lashed out at the United States for "alarming" actions, including "raising its voice louder for maintaining the sanctions against" North Korea.

The United States is pushing Pyongyang to denuclearize after the summit between President Donald Trump and North leader Kim Jong Un.

Trump hailed an agreement for North Korea to give up its nuclear weapons, but Pyongyang appears to have made slow progress toward that goal in the weeks since.

U.S. officials have urged all countries to maintain sanctions until Pyongyang achieves "the final, fully verified denuclearization" to which it has agreed.

Meanwhile, the United States has ramped up pressure on Tehran since Trump pulled his country out of the landmark 2015 nuclear deal, which provided Iran with some relief from financial sanctions in return for curbs on its nuclear program.

Media have reported on a growing number of protests on Iranian city streets as economic woes, many tied to U.S. sanctions against Tehran, have intensified.

According to media reports, United Nations and U.S. nuclear experts have expressed concern about interactions between North Korean and Iranian officials.

According to the Korean Central News Agency, Ri met with a high-level Iranian delegation at a meeting of the Non-Aligned Movement in Baku, Azerbaijan, in April.

A delegation from Pyongyang also attended Iranian President Hassan Rohani's August 2017 inauguration.

A 2017 report cited the presence of sanctioned North Korean weapons traffickers living in Tehran and similarities spotted between missile designs in the two countries, specifically Iran’s Shabab-3 and Khorramshahr missiles and North Korea’s Nodong and Musudan weapons.

Iran has said its nuclear program is strictly for civilian services.

With reporting by AFP, ChannelNews Asia, and TASS