The US envoy to South Africa warned on Thursday that a Russian ship had picked up weaponry in South Africa, potentially violating Pretoria’s professed neutrality in the Ukraine crisis.

The rand and South Africa’s 2030 government bond both fell further after the US declaration, with currency dealers concerned that South Africa might potentially face Western penalties.

When challenged about the cargo in parliament, South African President Cyril Ramaphosa would neither confirm or deny it occurred, but stated his administration was looking into it.

The U.S. ambassador to South Africa, Reuben Brigety, told local journalists in a briefing earlier on Thursday that Washington was confident a Russian vessel had uploaded weapons and ammunition from South Africa in December.

“Amongst the things we noted were the docking of the Russian cargo ship Lady R in Simon’s Town between Dec. 6 and Dec. 8, 2022, which we are confident uploaded weapons, ammunitions … as it made its way back to Russia,” Brigety said.

Senior U.S. officials had “profound concerns” Brigety added, in a recording of the briefing heard by Reuters. This “does not suggest to us the actions of a non-aligned country.”

Washington has repeatedly warned countries against providing material support to Russia, cautioning that those who do may be denied access to the world’s most important markets.

The U.S. State Department did not immediately respond to a request for comment. The U.S. embassy in South Africa and the U.S. Treasury Department declined to comment.

Brigety made the remarks to journalists following his return to Pretoria after accompanying a high-level South African delegation to the United States to address concerns about South Africa’s relationship with Russia.

“The matter is being looked into and in time we will be able to speak about it,” Ramaphosa told lawmakers in parliament.