The Kremlin kept silent on Sunday on a decision by sacked Prime Minister Viktor Chernomyrdin to stand for the Russian presidency as signs emerged that it may have been wrongfooted.

In another complication for President Boris Yeltsin, the leader of the opposition Communist Party said he would not back the Kremlin leader's choice of young, untested Sergei Kiriyenko to be prime minister.That increased the likelihood of a showdown between Yeltsin and the opposition-dominated State Duma, the lower house of parliament, which the president has threatened to dissolve if it does not approve Kiriyenko.

"He's worked for four months as a minister, he's 35 years old . . . To propose him for the post of prime minister is simply not serious," Communist Party leader Gennady Zyuganov told Reuters.

He said he was worried such an inexperienced and little-known politician could soon be just a heartbeat away from the trigger to Russia's nuclear arsenal.

Under the constitution, the prime minister stands in for the president if he is incapacitated. There is a precedent - Chernomyrdin took on Yeltsin's duties for less than 24 hours when the president had heart surgery in November 1996

Yeltsin, resting at a residence outside Moscow, did not react publicly to the latest political drama unfolding around him after a week of high-stakes maneuvers since he sacked Chernomyrdin and his entire government on March 23.

Chernomyrdin announced he planned to run in the next election, due in 2000, in a television interview on Saturday.

"Boris Nikolayevich Yeltsin and I discussed this, and I understood that he agreed with my position," Chernomyrdin said.

But in a sign that the presidential administration had been caught off guard, Interfax news agency quoted two apparently different unnamed administration officials whose remarks suggested the move had not been coordinated with the Kremlin.

One said it was "somewhat unexpected" and that Chernomyrdin did not necessarily have Yeltsin's unequivocal blessing. It also did not mean the president had decided not to run in the next election, Interfax's report said.

The agency quoted one unnamed administration official as saying the 67-year-old president had known Chernomyrdin intended to stand.