* Russian minister says can't understand NATO's criticism
* Lavrov says Iran nuclear deal removes need for NATO missile shield
* Lavrov asks if NATO plans to intervene in Ukraine, official says (Updates with U.S. official, Russia on NATO's missile defence plans)
By Adrian Croft and David Brunnstrom
BRUSSELS, Dec 4 Russia criticised "aggressive actions" by Ukrainian demonstrators and the Western response to the protests on Wednesday, saying outsiders should not interfere in Ukraine's affairs.
President Viktor Yanukovich's decision last week to spurn a trade and cooperation pact with the European Union in favour of closer ties with Russia has triggered days of mass protests.
"I do not quite understand the scope of the aggressive actions on the part of the opposition," Russian Foreign Minister Sergei Lavrov told a news conference after talks with NATO foreign ministers in Brussels.
Ukraine's government had used its sovereign right to decide whether or not to ratify an agreement, Lavrov said.
"I hope that Ukrainian politicians will be able to bring the situation into a peaceful vein. We encourage everybody not to interfere," Lavrov said, speaking through an interpreter.
NATO foreign ministers responded to scenes of Ukrainian police using batons and stun grenades to break up pro-Europe protests over the weekend by issuing a statement on Tuesday condemning the use of "excessive force" against protesters.
Lavrov said he did not understand "why NATO adopts such statements".
A senior U.S. State Department official who accompanied Secretary of State John Kerry to the Brussels meeting said Lavrov had asked NATO foreign ministers whether their statement meant the alliance had plans to intervene in Ukraine.
"All allies made clear that this was firmly about supporting the aspirations of the Ukrainian people for a European future, that there was no military operation planned in Ukraine, and it was provocative to discuss that," he said.
European Union foreign policy chief Catherine Ashton asked Kerry in a separate meeting to work together with the EU to help the cash-strapped Ukrainian government and the opposition work on a road map back to Europe and to the International Monetary Fund, the U.S. official, speaking on condition of anonymity, said.
Lavrov said he argued in the talks with NATO ministers that the alliance would have no need to push ahead with its plans to build a missile defence system if Iran and world powers reached a final agreement on Tehran's nuclear programme.
U.S. and NATO plans to build an anti-missile shield around Western Europe to protect against attack from Iran and North Korea have been a major irritant in relations with Russia, which fears the system's interceptors could eventually shoot down its long-range nuclear missiles.
Last month, Iran and six world powers, including Russia, clinched an interim deal to curb the Iranian nuclear programme in exchange for initial sanctions relief.
"We noted that if the arrangement is implemented fully ... then there will be no reasons for creating a missile defence system in Europe," Lavrov told reporters.
Kerry and other alliance foreign ministers strongly disputed Lavrov's contention, the senior State Department official said.
In separate talks with Lavrov, Kerry argued that missile defence protection was needed because "it is not only about Iran's nuclear programme, it's also about its ballistic missile programme, which allows it to deliver other forms of WMD (weapons of mass destruction) as well," the official said. (Editing by Ralph Boulton)