The letter was in response to Trump's call last month for the former war foes to strike a deal to end their dispute, saying his government was ready to assist.

Trump's outreach came as long-running EU-led talks between Kosovo and Serbia, which refuses to recognise its former province's independence, have stalled in recent months.

In the letter dated January 8, Kosovo President Hashim Thaci assured Trump he would be "ready and willing to make compromises necessary to reach a comprehensive and balanced settlement that will encompass all outstanding issues...with Serbia".

Kosovo, which is home to an ethnic-Albanian majority, broke away from Serbia in a bloody 1998-99 guerilla war and declared independence a decade later, with strong backing from Washington.

But Belgrade has never accepted the split and has waged a diplomatic campaign to undermine Kosovo's legitimacy and shut it out of organisations like the United Nations.

In his letter to Trump, Thaci said he agreed a deal was "now within reach."

Domestic opposition

Thaci has also battled strong domestic opposition to his approach to the talks with his Serbian counterpart Aleksandar Vucic.

Critics have lambasted the president's calls for making "border corrections" with Serbia as part of a deal.

Though the plan has never been spelled out concretely, local media and analysts assume the "land swap" would see Kosovo's Serb-dominated northern region traded for a mainly ethnic-Albanian section of Serbia.

Kosovo's Prime Minister Ramush Haradinaj, who takes a hard-line approach towards relations with Serbia, has been one of the leading critics of the proposal.

He refuses to lift a 100 percent tariff his government slapped on Serbian goods last year unless Belgrade shows a willingness to recognise Kosovo.

On Tuesday Haradinaj said he would not back down from a list of demands he wants met before lifting the tariff -- ranging from ruling out border changes with Serbia to granting Kosovo citizens visa-free travel in the EU.

"If one of the conditions that I have issued ruins (my relations) with someone, no worries" the tough-talking premier told media, despite repeated EU and US calls to lift the tariff.

But parliament speaker Kadri Veseli, who chairs Thaci's ruling party PDK, on Tuesday also urged a freeze of the tariff.

If the premier's party breaks from PDK's ruling coalition, it would lose its majority and risk facing early elections.

Kosovo in December passed laws to build an army, asserting its statehood in a US-backed move that further increased tensions with Serbia, which said the decision had crossed the line.

Kosovo has been guarded by NATO-led peacekeeping troops since it broke away from Belgrade in its separatist war before declaring independence in 2008.