UNITED NATIONS, Aug 28 (Reuters) - Russia pledged at the United Nations on Monday (Aug 28) to keep providing "comprehensive assistance" to Mali, where about 1,000 fighters with Russia's Wagner mercenary group are helping the West African state's junta fight an Islamist insurgency.

Wagner chief Yevgeny Prigozhin died in a plane crash last week and Russian President Vladimir Putin then ordered Wagner fighters to sign an oath of allegiance to the Russian state.

Russia's Deputy UN Ambassador Dmitry Polyanskiy said that bilateral cooperation between Russia and Mali and the military junta's "sovereign choice" of international security partners "are keeping our former Western partners up at night".

"Russia, for its part, will continue to provide Mali and other interested African partners with comprehensive assistance on a bilateral, equal and mutually respectful basis," he told the UN Security Council.

The 15-member council in June voted to end a decade-long peacekeeping mission in Mali after the military junta abruptly asked the 13,000-strong force (MINUSMA) to leave - a move the United States said was engineered by the Wagner group.

Mali has struggled to stem the Islamist insurgency that took root following an uprising in 2012. UN sanctions monitors reported to the Security Council this month that "in less than a year, Islamic State in the Greater Sahara has almost doubled its areas of control in Mali".

Mali's junta, which seized power in coups in 2020 and 2021, teamed up with Wagner in 2021.

"As many of us feared, the transition government's decision to close MINUSMA has already triggered renewed violence on the ground," US Ambassador to the United Nations, Linda Thomas-Greenfield, told the Security Council on Monday.

"Additionally, MINUSMA's withdrawal limits the ability of the international community to protect civilians from the predations of Wagner, whose activities contribute to greater insecurity in the country," she said.