World Bulletin / News Desk

US President Donald Trump signalled support for Ukraine's territorial integrity in a letter released on Friday, as Kiev grapples with an upsurge in fighting with Russia-backed separatists.

"Your support for the sovereignty and territorial integrity of Ukraine (…) advance our shared goal to enhance European and regional security," Trump said in a letter to Lithuanian President Dalia Grybauskaite.

The US embassy įn Vilnius published the letter amid the worst fighting in two years in eastern Ukraine, which has presented the Trump administration with the first test of its Russia policy.

After an uprising in Kiev ousted a pro-Russian leader, Moscow annexed Ukraine's Crimean peninsula in March 2014 and supported a separatist movement in eastern Ukraine that has since claimed more than 10,000 lives.   

Trump, who has suggested he may seek to improve ties with Moscow, praised Lithuania's defence spending hike, calling it a "valued NATO ally".

Vilnius increased its defence budget by a third this year and pledged to meet NATO's two-percent-of-GDP funding target in 2018. 

Grybauskaite said Thursday that Lithuania "trusts" Trump will fulfil all US defence obligations towards its NATO partners.

Her comments come at a time of uncertainty for eastern NATO allies like Poland and the three Baltic states, who have been unsettled by Trump's seemingly pro-Moscow stance coupled with critical remarks about NATO. 

Trump has called the alliance "obsolete" in terms of fighting terrorism, but of "fundamental importance" to transatlantic security.

The new US president sent the letter to congratulate on its upcoming February 16 national holiday.