US State Department welcomed the president's decision, calling it "the right decision" [GALLO/GETTY]

Kazakhstan's president has called for a snap presidential election on April 3.

Friday's presidential decree will end Nursultan Nazarbayev's current term in office about 20 months before it was due to end.

Earlier, Nazarbayev rejected a plan to hold a referendum which was designed to allow him to rule unopposed for another decade.

Nazarbayev, 70, has ruled Kazakhstan for two decades and is almost certain to win the snap election he called.

Analysts say the opposition, which was caught off guard by the announcement, would simply not have enough time to prepare for the polls.

The United States, which warned in December that skipping elections through a referendum would be a "setback for democracy", promptly hailed Nazarbayev's decision to hold an early election.

The OSCE, Europe's main security and rights body, welcomed Nazarbayev's decision to hold a snap election, saying that Kazakhstan had promised to hold "democratic elections at reasonable intervals" at a recent OSCE summit in Astana.

But critics say that Nazarbayev's election call is largely designed to pacify the West.

Nazarbayev, known as 'Papa' to many Kazakhs, can run for an unlimited number of terms. Kazakhstan has never held an election judged free and fair by international observers.

By rejecting the "people's referendum initiative", Nazarbayev showed his resolve to secure firm Western backing and extend diplomatic gains achieved last year when Kazakhstan became the first former Soviet country to chair the OSCE.

Many foreign investors, who have poured more than $150bn into Kazakhstan during Nazarbayev's rule, rate the absence of a clear succession plan as the single biggest threat to political stability in the oil-rich country.

Nazarbayev, a former steelworker who has put in place bold market reforms, brooks no dissent, and the vast country of 16 million has no organised opposition movement.

Along with Uzbek President Islam Karimov, who rose to power at the same time, Nazarbayev is the longest ruling ex-Soviet leader.

Source: Agencies