Striking coal miners in northern Russia have rejected an appeal to resume shipments to a fuel-starved metal plant, defying an order by President Mikhail S. Gorbachev, news reports said Saturday.

Workers in two key industrial cities in the Ukraine pledged to hold general strikes this week demanding political changes, and nationalists in the rebellious southern republic of Georgia flouted a presidential order by extending their control Saturday over a separatist region.The developments were additional blows to Gorbachev's attempt to ban strikes and rallies while implementing a package of "anti-crisis" economic reforms. Gorbachev has little support among average Soviets and almost none among the striking workers, who have made his resignation a chief demand of their spreading labor protest.

Gorbachev issued a decree Friday ordering republic and local officials to "abolish within a week's time decisions forbidding the export of products out of the republics, regions or districts," according to the state news agency Tass.

The decree did say not what would happen if supplies do not resume. There appeared to be no way Gorbachev could enforce the decree short of force.

Municipal leaders in the Ural Mountains city of Vorkuta, a major coal basin, said they received a telegram Friday from the Russian Federation government asking them to make sure coal is delivered to the Cherepovetsk metal plant north of Moscow, said the independent news agency Postfactum.

Vorkuta miners, in a meeting Friday, rejected the appeal "as an attempt to put pressure on miners," Postfactum reported. They voted instead to continue their strike indefinitely until all political demands are met.

The Vorkuta miners are among an estimated 300,000 on strike nationwide. The walkout began at several mines March 1 as bid for better pay, and has spread to other industries with political demands including Gorbachev's ouster and transfer of national power to leaders of the 15 republics.

The government newspaper Izvestia printed figures Saturday showing an 82 percent drop in coal production since the strike began.

Metallurgy workers in the Ural Mountains city of Chelyabinsk endorsed the miners' demands on Friday and voted to take action themselves unless officials consider their demands by April 20, Tass said.

Oil workers in Siberia also have demanded the government start talks on profit-sharing or they would take some kind of action.

Following the lead of 200,000 Byelorussian factory workers who held a 11/2-day strike last week, workers in the Ukrainian capital of Kiev and mining center of Donetsk pledged Saturday to hold warning strikes this week.

A one-day strike and rally was set for Tuesday in Kiev, a city of 2.6 million, in support of miners and their demands, the reformist newspaper Nezavisimaya Gazeta reported.

It "could become some sort of preparation to a general political strike in the Ukraine," the newspaper quoted strike committee member Leonid Kovalchuk as saying.