MOSCOW (AFP) - Russia said on Thursday it had finally got Brussels and Kiev to include it in talks over a landmark association agreement between Ukraine and the European Union to be signed this week.

"We have lots of questions. The Russian side has handed over a special note about its concerns," deputy foreign minister Alexei Meshkov told the state news agency ITAR TASS in Vienna.

"Finally, agreement has been reached today on a trilateral format, a meeting at the level of technical experts is possible literally today or tomorrow," Mr Meshkov was quoted as saying. "And, at the request of the EU, a ministerial meeting should take place in mid-July."

Much to Russia's chagrin, Ukrainian President Petro Poroshenko on Friday is set to sign the final chapters of the landmark EU pact in Brussels.

His predecessor Viktor Yanukovych's abrupt decision to put the key trade and political agreement on ice under pressure from Moscow in November sparked huge Kiev protests that eventually led to his ouster.

Moscow has for months insisted it should be part of trade and political talks between Brussels and its former Soviet neighbour, expressing concern that the agreement will hurt its economic interests.

Russia has threatened to protect its markets by imposing higher tariffs on Ukrainian goods.

Separately, Mr Meshkov accused the United States of seeking a pretext to slap tougher sanctions against Russia over the Ukraine crisis.

"All this ongoing talk of sanctions is absolutely logical and it's completely obvious that there are certain forces, first and foremost the United States, which are extremely interested in seeing sanctions introduced against Russia under any contrived pretext," he said. "Therefore it does not depend on us whether sanctions against Russia will be introduced or not."

US Secretary of State John Kerry warned earlier on Thursday that Russia must prove "in the next hours" that it is working to help disarm separatist groups in restive eastern Ukraine.