A test launch of a Russian Soyuz rocket with a new engine design has been delayed until 2014, officials said without specifying a new date.

"The launch has been postponed until next year," defense official Colonel Dmitry Zenin said.

The new Soyuz-2.1v features a completely reworked first stage powered by a new-design rocket engine built by the NK Engines Company in the Russian city of Samara.

Originally scheduled for Monday, and then postponed twice, officials decided to push the test launch to next year over concerns of a possible malfunction of one of the rocket's engines, a space industry source told RIA Novosti.

The Soyuz and the Chinese Long March 2F are currently the only two operating rockets in the world capable of sending astronauts into space; all astronauts on the International Space Station have arrived aboard Soyuz spacecraft.

Since its debut in 1966, the Soyuz design has been used for more than 1,700 launches.

Soyuz missions currently take place at three locations -- Baikonur in Kazakhstan, Plesetsk in northwest Russia and the European Kourou center in French Guiana.