The United States on Wednesday expanded its sanctions against Myanmar to include foreign companies or individuals helping the country's military junta to procure jet fuel that it uses to launch airstrikes on its own people, the US Treasury Department said in a statement.

The Treasury was also adding to its sanctions list two individuals, Khin Phyu Win and Zaw Min Tun, as well as three companies linked to them, who are involved in procurement and distribution of jet fuel for the military, which seized power in a February 2021 coup, it said.

The Treasury said it was issuing a determination that identifies the jet fuel sector in Myanmar as covered by an executive order signed by President Joe Biden blocking companies outside of Myanmar from dealing with the country's defense sector.

"By expanding the use of our sanctions authority to target an additional sector critical to the military regime, we are able to further deprive the regime of the resources that enable it to oppress its citizens," Brian Nelson, under secretary of the treasury for terrorism and financial intelligence, said in the statement.

Myanmar's junta "has increasingly relied on violent airstrikes to repress the people of Burma," Treasury said, using the country's former name, citing recent strikes that killed civilians and estimating that the military junta has killed more than 3,900 civilians since the coup

Myanmar military officials, who have played down the impact of sanctions, say they are targeting insurgents.

The United States and other Western nations have imposed multiple rounds of sanctions on Myanmar's military leaders since the coup in which they overthrew the democratically elected government led by Aung San Suu Kyi, killed thousands of opponents in a crackdown, and sparked a bitter insurgency.

Washington in June targeted two state-owned banks used by revenue-generating state-owned enterprises, including the Myanma Oil and Gas Enterprise, to conduct currency exchange, in a move activists hoped would cut off the junta's access to foreign currency.