* NATO orders out two Russian diplomats
* Russia promises "harsh and decisive" response
* Expulsions on same day as NATO-Russia formal ties resumed
* NATO criticises Russian pacts on Georgian rebel areas
(Wraps expulsions and Georgia statement, Russian reaction)
By David Brunnstrom
BRUSSELS, April 30 (Reuters) - NATO has expelled two Russian diplomats over a spy scandal, a move Moscow’s ambassador said was intended to set back efforts by Russia and the United States to repair relations.
Tensions between the former Cold War foes also rose on Thursday over pacts which Moscow said gave it control over the borders of two rebels regions in Georgia.
The expulsions were a new blow to prospects of improving relations between Moscow and NATO, one week before alliance military exercises in Georgia which have angered Russia.
"Two Russian diplomats have been told they are not welcome here," a NATO diplomat said.
Russia’s ambassador to NATO, Dmitry Rogozin, told reporters in Brussels the Russian response would be "harsh and decisive".
The pair were attached to the mission which Russia has at NATO headquarters, although it is not a member of the military alliance.
The diplomat said they were expelled over the case of Herman Simm, an Estonian jailed for more than 12 years for treason in February for handing more than 2,000 pages of information to handlers in Russia’s SVR Foreign Intelligence Service.
NATO ordered the diplomats out on the same day the alliance resumed formal talks with Russia at ambassadorial level, eight months after contacts were suspended over Russia’s five-day war with Georgia last August.
Russia said the expulsions were driven by elements inside the Western alliance that wanted to undermine ties with Moscow.
"A crude provocation has been made in relation to two employees of Russia’s permanent mission to NATO on an absolutely trumped up pretext without any clear explanation," Russia’s Foreign Ministry said in a statement.
ROW OVER PACTS WITH REBEL REGIONS
The 28-nation alliance separately criticised pacts giving Russia direct control over the de-facto borders of Georgia’s South Ossetia and Abkhazia regions.
Russia took formal control over the borders of the two regions under the agreements, which were signed by Russian President Dmitry Medvedev.
NATO spokesman James Appathurai said the signing of the pacts contravened the peace deals brokered by the EU after Russia’s brief war with Georgia last August.
"This is in clear contravention of the 12th August and 8th September agreements negotiated by the European Union and is not in the interests of long-term peace and security in the South Caucasus region," Appathurai told reporters.
Russia regards improving relations with NATO as part of a broader effort to improve relations with the West, and in particular with the United States. Ties with Washington sank to a post-Cold War low under U.S. President George W. Bush.
Medvedev said on Thursday that NATO’s May 6 war games amounted to a challenge from the West.
One of the expelled Russians was the son of Vladimir Chizhov, Moscow’s ambassador to the European Union, NATO officials said.
Simm worked at the Estonian Defence Ministry from 1995 to 2006 and had access to top secret documents, including those related to NATO, which Estonia joined in 2004.
Estonian media said information Simm passed to the Russians included documents on foreign countries’ and international organisations’ communication and information systems, data security, intelligence, counter-intelligence and defence policy.
Estonia quit the former Soviet Union in 1991 and, along with its Baltic neighbours Latvia and Lithuania, made integration with the West via NATO and the European Union a top priority. (Writing by Mark John)