Ukraine's foreign minister denounced Russian "provocations" Monday, warning of a troop build-up on the border and the presence of "political tourists" in its eastern regions.

"We are very much concerned by the number of Russian troops on the (border)," Foreign Minister Andriy Deshchytsya said after talks with NATO head Anders Fogh Rasmussen.

Kiev's interim government was also worried by "the number of Russian political tourists in eastern Ukraine regions and with the number of provocations Russians are trying to organise," Deshchytsya said.

He said the situation looked very similar to that in Georgia in 2008 when Russia sent in troops to secure the independence of two breakaway regions, Abkhazia and South Ossetia.

Ukraine was being careful not to be duped into a military escalation, he said.

"We are instructing our military, and also suggest other people, not to go for provocations," he said, stressing Kiev's efforts to use "diplomatic means to solve and settle this conflict peacefully."

Rasmussen made no separate comment but has said earlier he views Russian intervention in Ukraine, and especially in Crimea, as a threat to European security.

Deshchytsya, speaking just as the pro-Russian assembly in Crimea declared independence and asked formally to join Russia, called for stepped up cooperation with NATO.

This would be done under existing links with the US-led military alliance and cover such things as technical help and stepped up exercises.

Ukraine has not asked for a NATO "military presence," the minister said.

Ukraine signed a partnership accord deal with NATO in 1997 after the fall of communism and the end of the Soviet Union, but is not a full member so does not come under its protective umbrella.

The alliance agreed at a 2008 summit that Kiev could seek full membership, as other former Soviet satellites such as Poland have done.

That move infuriated Moscow and two years later, the now ousted pro-Russian leader Viktor Yanukovych ditched this option.