US defence secretary James Mattis has hailed his country's "unbreakable" ties with Europe at talks with Balkan security chiefs, as Russia grumbled about Nato's role in the region before a summit between Donald Trump and Vladimir Putin.
Ahead of Monday's meeting in Helsinki between the US and Russian presidents, Mr Mattis insisted that Washington was still engaged in the Balkans, amid concerns that Moscow could exploit any absence of White House interest in the strategic area and the EU's preoccupation with Brexit and migration issues.
“We are not naive and we are keenly aware that some elsewhere would wish to see us fail in our endeavours here today,” Mr Mattis said on Friday, in obvious reference to Russia.
“Those that seek to divide us for their own reasons will not enjoy our dedication to working together,” he added before talks began in the Croatian capital, Zagreb. “Our meeting today is proof of unbreakable transatlantic relations.”
Mr Mattis arrived from a fractious Nato summit in Brussels, where Mr Trump upbraided US allies for paying too little into the organisation's coffers, but the Pentagon chief insisted his country was "100 per cent committed" to the alliance.
At a meeting with Croatian prime minister Andrej Plenkovic on Thursday evening, Mr Mattis said the Pentagon would continue to help Zagreb upgrade its military, following the donation of 16 combat helicopters in 2016.
“America follows everything that is happening in southeastern Europe and wants to make its contribution to the stability of that area,” Mr Mattis told his host.
Russia accuses the US and Nato of stoking unrest in a region that is still recovering from inter-ethnic 1990s wars, but last year it pledged to donate ageing MiG fighter jets, tanks and other armoured vehicles to its main regional ally, Serbia.
Belgrade's defence minister Aleksandar Vulin did not attend Friday's gathering, having been declared persona non grata by Croatia during a row in April.
“Serbia will remain militarily neutral and free . . . even if it remains the only [Balkan] country which is not a Nato member,” Mr Vulin said on Friday.
After Nato asked Macedonia to become its 30th member if it changes its name under a long-awaited deal with Greece, Moscow's foreign ministry said the expansion of the alliance "does not in any way strengthen security but deepens dividing lines and feeds tension in Europe".
Greece this week announced it was expelling two Russian diplomats and placing entry bans on two other Russians for allegedly trying to bribe local officials and encourage protests against the historic deal with Macedonia.
Russia’s foreign ministry summoned the Greek ambassador over the issue on Friday, and warned that Athens’ actions “could seriously damage relations”.
“It is obvious that Washington stands behind this anti-Russian decision by the Greek government,” the ministry added.