US envoy to Kosovo and Serbia Richard Grenell says Kosovo's plan to partially lift a tariff on Serbian imports is unacceptable and "must be completely dropped."
Kosovo's premier faced a backlash on Friday for his plan to partially lift a tariff on Serbian imports, with a US diplomat condemning it as a "serious mistake" for falling short of full removal.
The West has been pressuring Kosovo for months to drop the trade barrier.
But the "half measure" Kosovo's Prime Minister Albin Kurti announced on Thursday was met with disapproval from Richard Grenell, the outspoken US envoy to Kosovo and Serbia who was also recently named President Donald Trump's acting intelligence chief.
"We do not support Prime Minister Kurti's half measure," Grenell, known for his blunt approach, wrote on Twitter.
"Our position is quite clear: the tariffs must be completely dropped. Mr Kurti is making a serious mistake," he continued.
The tariff dispute has formed the latest chapter in turbulent ties between the Balkan neighbours, who have yet to normalise their relationship since Kosovo, broke away in a 1998-99 war.
Under Kurti's plan the tariff, which has become the latest source of animosity between Kosovo and Serbia, would be first lifted on raw materials.
It would then be scrapped in full in April, but only if Serbia also shows signs of goodwill, Kurti said.
The newly-elected premier also received blowback from both allies and opponents at home.
Kurti's key coalition ally, the LDK party, threatened to quit the government if the tariff was not "revoked unconditionally," deputy Prime Minister Avdullah Hoti told local media.
"Can a government that does not enjoy the United States' support govern successfully?" he asked.
EU welcomes move
Kurti did, however, get measured support from the EU, who welcomed the "first step" towards resuming the EU-led talks between Serbia and Kosovo.
Serbia has never recognised the independence that Kosovo declared in 2008 and has lobbied hard to keep it out of global organisations, including the United Nations.
After it was levied in late 2018, the tariff brought EU-led negotiations between the neighbours to a standstill.
The US, however, has been working a different angle, with Grenell recently bringing the two sides together to work on improving their transportation links.