Russian military build-up

NATO Secretary General Jens Stoltenberg on Tuesday called on Russia to pull back troops from within Ukraine as well as its side of the Ukrainian border and to "contribute to a peaceful agreement."

Speaking as he arrived at a meeting of European Union defence ministers in Brussels, Stoltenberg described the military build up of Russian troops and sophisticated equipment as "very serious."

Meanwhile, Germany's foreign minister, Frank-Walter Steinmeier, traveled to Ukraine's capital, Kyiv on Tuesday for talks with President Petro Poroshenko and Prime Minister Arseniy Yatsenyuk. He was also to travel on to Moscow later in the day in a bid to revive a faltering peace plan between Ukraine and pro-Russia separatist rebels, that the two sides signed in the Belarusian capital, Minsk, two months ago.

Fragile ceasefire

While in Kyiv, Steinmeier called on Ukraine and Russia to abide by the terms of the ceasefire included in the peace plan.

"The agreements were not perfect but they do form a basis. We have to fulfill the agreements," Steinmeier said.

"Last weekend in Brisbane there were a lot of talks with the Russian president including the German chancellor with Mr Putin," said the foreign minister. "So now I am here and this afternoon ... I will set out to see if these talks in Brisbane have created an atmosphere where we can work more concretely to implement the Minsk agreement," he added.

'It affects us all'

Steinmeier was referring to a two-hour-long meeting that Chancellor Angela Merkel had with President Vladimir Putin on the sidelines of the G20 summit at the weekend. Merkel, however, later gave a pessimistic account of the talks, in which she warned of Russian interference in other parts of Europe and wider ramifications.

"The Ukraine crisis is most likely not just a regional problem," Merkel said in a speech at the Lowy Institute for International Policy in Sydney on Monday. "In this case, we see it affects us all," she added.

Referring specifically to Russia's move to annex Crimea in March, Merkel said it had "called the whole of the European peaceful order into question, and it has continued by Russia exporting its influence to destabilize eastern Ukraine."

New sanctions

During talks in Brussels on Monday, Steinmeier and the European Union's other 27 foreign ministers agreed to impose travel bans and asset freezes on more pro-Russia separatists fighting in Ukraine by the end of the month. However, they stopped short of imposing fresh sanctions on Russia over its alleged active support of the rebels.

ksb/pfd (Reuters, AFP, dpa)