The United Nations on Monday said that the letter sent by North Korea over the United States' seizure of its cargo ship is under review.
On May 8, the US Justice Department said it seized Wise Honest, one of North Korea's cargo ships on suspicions of transferring coal and machinery in violation of sanctions imposed on Pyongyang by Washington and the UN.
The 17,061-ton bulk carrier was also intercepted by foreign maritime authorities in April last year after being loaded with coal in Nampo, North Korea, the department said in a press release.
Following the ship seizure, North Korea's top envoy to the UN, Kim Song, sent a letter to Secretary-General Antonio Guterres, last Friday, seeking "urgent measures" against the US' decision and criticising the move as "unlawful and outrageous".
Confirming receipt of the letter, Stephane Dujarric, spokesman for the UN chief, said the letter has been "distributed and circulated ", Yonhap reported.
"We are, obviously, studying the letter as ... it relates to the issue of sanctions on the DPRK and actions taken in the implementation of those sanctions," Dujarric was quoted as saying in a press briefing in New York on Monday (local time).
"The questions relating to possible sanctions evasion and Member States' implementation of Security Council resolutions are a matter for Member States to address," he added.
According to North Korea's state-run newspaper Korean Central News Agency, leader Kim Jong-un is set to hold a briefing on the seizure of the ship at the UN headquarters in New York on Tuesday.