Now, increased trade efforts between the two heavily sanctioned countries have raised concerns that they could share advanced missile and nuclear technology.

Coming at a time when Tehran and Pyongyang are playing a central role in heightened global tensions, the prospect of one pariah state in possession of nuclear weapons and intercontinental missiles, North Korea, aiding another accused of seeking those capabilities, Iran, has heightened fears in Western capitals.

The visit of a North Korean delegation to Tehran last month only served to increase suspicions.

Washington and Brussels both expressed concerns about any sanctions-violating cooperation, prompting Tehran to insist that the visit by North Korea’s external economic relations minister was aimed only at improving economic ties and assertions that it is seeking to expand cooperation on missile technology were "untrue."

But allegations that North Korean military technology has shown up in the hands of Iranian proxies in the Middle East and aided Iran's missile and drone attack against Israel last month have fueled concerns.

"North Korea's nuclear program is obviously something that the Iranians seek to emulate," said Benjamin Young, a North Korea expert at Virginia Commonwealth University. "North Korea's ability to develop nuclear weapons at a rapid scale is admirable to the Islamic republic."

Pyongyang also has a long-range delivery vehicle in its Hwason-15 intercontinental ballistic missile, which is capable of carrying a heavy payload and of reaching the mainland United States.

"North Korea has made strides with very long-range-capable missiles, and that's something that Iran could be interested in," said Kenneth Katzman, a senior adviser for the New York-based Soufan Group intelligence consultancy and an expert on geopolitics in the Middle East.

North Korea has cultivated a military partnership with Tehran for decades, including the provision of conventional weapons to the Islamic republic during the Iran-Iraq War in the 1980s and help in the 1990s in developing Iranian ballistic missiles.

The North Korean delegation's visit to Tehran, coming just a month after a similar visit to Moscow, raised concerns that Pyongyang could be entering a broader partnership involving Iran and Russia. That prospect has gained attention with North Korea's reported provision of munitions to aid Russia's war effort in Ukraine.

GunazTV