Ukraine-Russia Conflict: Trump cancel Putin talks'

The United States President Donald Trump has cancelled a planned meeting with his Russian counterpart Vladimir Putin over a naval clash between Ukraine and Russia.

Trump was scheduled to meet Putin at the G20 summit in Buenos Aires at the end of this week. but Trump said on Thursday he would not meet Putin at a G20 summit in the coming days, "based on the fact that the ships and sailors have not been returned".

German Chancellor Angela Merkel blamed the crisis "entirely" on Russia.

She said she would raise the issue with President Putin at the G20 meeting, which is due to be held in Argentina on Friday and Saturday.

Ukrainian President Petro Poroshenko earlier warned that the standoff could herald more drastic developments as tensions escalate between the ex-Soviet neighbours.

Poroshenko has urged Nato to send ships to the area. He has implemented martial law across Ukraine's border regions for 30 days in response to the crisis.

On Sunday Russian border guards fired on three Ukrainian ships and seized their crews off the Crimean Peninsula.

The move stoked already high tensions between Moscow and Kiev, as Russia continues to accuse the sailors of crossing illegally into Russian waters and of ignoring warnings from its border guards.

Kiev has demanded the release of the sailors and urged Western allies to impose further sanctions on Moscow.

The US State Department has termed Russia's actions "a dangerous escalation" and said Washington wants to see "our European allies doing more to assist Ukraine."