Kosovo President Hashim Thaci bowed to pressure from traditional allies the United States and NATO on Friday by putting off plans to establish an army strongly opposed by the country’s minority Serbs.

Nearly two decades after the Kosovo war, relations between Serbia and the ethnic Albanian-majority government in Kosovo remain strained. Serbia continues to regard Kosovo, which declared independence in 2008, as a renegade province.

Thaci last month found a way to bypass Serb opposition in parliament to constitutional amendments required for an army by drafting changes to an existing law on the Kosovo Security Forces that would allow the KSF to acquire heavy weapons. This would effectively turn it into a military force.

But Washington and NATO, which has kept forces in Kosovo since intervening in 1999 to stop Serbia’s killings of ethnic Albanian civilians in a counter-insurgency campaign, voiced concern that the move could unravel Kosovo’s fragile peace.

The Pristina government ordered the creation of a national army in 2014 but minority Serb deputies said they would block the required constitutional amendments.

On Friday, Thaci – a former Kosovo guerrilla commander – sent a letter to parliament asking it not to vote on his amendments so as to allow Western diplomats more time to convince Serbs to approve the amendments.

“The representatives of the Serb community should not think for any single second that Kosovo will not create its armed forces,” Thaci told a conference in the capital Pristina attended by the U.S. ambassador and other West European envoys.

The KSF is currently a lightly armed, 2,500-member force trained by NATO and tasked with crisis response, civil protection and disposal of ordnance from the 1999 conflict.

NATO and the United States do not oppose the creation of an army in principle but say the constitution must be changed first, which would require the votes of 11 Serb deputies in the 120-seat parliament.

“We do not expect the people of Kosovo to wait forever on this [formation of the army], nor do we believe any party should veto,” U.S. Ambassador Greg Delawie said.

“Kosovo needs a legitimate capability to defend itself before KFOR [NATO mission] can consider leaving.” KFOR retains around 4,500 troops in Kosovo.