LONDON (AP) _ World leaders on Sunday reaffirmed support for Russian President Boris Yeltsin in his showdown with hard-liners who are trying to thwart his economic and political reforms.

Prime Minister Carl Bildt of Sweden said he regretted Yeltsin's imposition of emergency rule on Saturday, but added that if the gamble works, it could strengthen democracy in the long run.

Others suggested Yeltsin has the moral high ground and the popular mandate as Russia's first democratically elected leader. His main nemesis, the Congress of People's Deputies, was chosen during the Soviet era and is dominated by pro-Communists and hard-liners.

''The British government has always supported the process of reform in Russia,'' the Foreign Office said in a statement. ''We reaffirm our support for the reform process.''

Britain and other members of the Group of Seven, the world's richest industrialized nations, said consultations were continuing about an aid package to bolster Russia's moribund economy.

The G-7 - the United States, Britain, Germany, Japan, Canada, France and Italy - is scheduled to meet this summer in Tokyo. But some members, notably France and Canada, are pushing for an emergency meeting on Russian aid, possibly following Yeltsin's summit with President Clinton in Vancouver on April 3-4.

Clinton said Saturday the Vancouver summit was still on and that he was ''encouraged'' by Yeltsin's promise to respect civil liberties leading up to an April 25 referendum on how Russia should be governed.

''As Russia's only democratically elected national leader, he has our support, as do his reform government and all reformers throughout the Russian federation,'' Clinton said in a statement read by his chief spokesman, George Stephanopoulos.

Canada's prime minister, Brian Mulroney, ''underlined Canada's support for President Yeltsin's decision to let Russia's people exercise the right to choose their own future,'' according to a statement issued by his office.

A Japanese Foreign Ministry statement reiterated support for Yeltsin's economic, political and foreign policy reforms.

London's Observer newspaper cautioned that Western governments cannot rush to commit themselves to an aid package without knowing whether Yeltsin will triumph over the hard-liners.

''But whenever there is a chance, the West must nudge Yeltsin and his country towards democracy. It is our only option, and surely best for the long-suffering Russia, too.''