KIEV (Reuters) - Ukrainian President Petro Poroshenko on Tuesday granted citizenship to three foreign technocrats nominated for cabinet positions in a new government hoping to tackle severe economic and defense threats.

Parliament is expected to vote on nominees for cabinet positions on Tuesday with Kiev under pressure to form a new government quickly.

Ukraine has been offered billions of dollars in aid by international lenders if it implements a program of economic reform and Poroshenko said the administration would benefit from international specialist input.

"There are absolutely extraordinary challenges facing Ukraine - an extremely difficult economic situation, Russian aggression, the need for radical reform and the fight against corruption. All this requires innovative solutions in the government," he said in statement.

"These decisions mean searching for candidates for the new government not only in Ukraine but also abroad," he said.

One of the three is Natalie Jaresko, a U.S. citizen and chief executive of private equity group Horizon Capital. She has worked in Ukraine for more than 20 years after holding various economic positions in the U.S. State Department.

The other two are Lithuanian Aivaras Abromavicius, a partner in investment firm East Capital, and Georgian Aleksander Kvitashvili, who has served as health minister and labor minister in Tbilisi.

Prime Minister Arseniy Yatseniuk submitted a list of candidates nominated by the coalition to parliament. It showed Jaresko up for the role of Finance Minister, Abromavicius for Economy Minister and Kvitashvili for Health Minister.

(Editing by Louise Ireland)