Belarus's top diplomat arrived in Pyongyang for a four-day visit, North Korean state media said Wednesday, as the two heavily sanctioned countries look to deepen ties.

"At the invitation of the Foreign Ministry of the DPRK, Maxim Ruzenkov, foreign minister of the Republic of Belarus, arrived here on Tuesday to pay an official visit," the official Korean Central News Agency said.

Ruzenkov's trip comes as the two states strengthened ties with Russia amid the ongoing war in Ukraine.

North Korea will "deepen ties with Minsk on all fronts to open a new era of improved relationships," Foreign Minister Choe Son-hui said at a dinner welcoming the Belarusian delegation.

Ruzenkov was reported as saying Belarusian President Alexander Lukashenko and North Korean leader Kim Jong-un both hoped to nurture a closer relationship.

Last month, the European Union agreed on new sanctions against Belarus over its role in the Ukraine war.

In June, Russian leader Vladimir Putin made his first visit to North Korea in 24 years and signed a strategic treaty with leader Kim, including a commitment to come to each other's aid if attacked.

Seoul and Washington have accused North Korea of supplying ammunition and missiles to Russia for its war, and the new treaty has fuelled fears of more deliveries. (AFP)