A coalition of opposition parties on Sunday triumphed in Venezuela's parliamentary election and won more than twice the number of National Assembly seats as embattled President Nicolás Maduro's ruling United Socialist Party of Venezuela.

Partial results suggested the socialists would take 46 seats in the new parliament, while its challengers will claim at least 99, Reuters reported. Even though details were not yet in for the remaining 22 seats, the opposition looks certain to reach a three-fifths majority.

Opposition leaders immediately promised on Monday to use their new majority in Venezuela's National Assembly to free jailed dissidents of Maduro's government but to show restraint when it comes to going after their political rivals.

"We have been divided for years and the country has gained nothing from this mistake in its history," said Jesus Torrealba, the head of the Democratic Unity coalition. "The (opposition bloc) is not here to mistreat anyone."

Henrique Capriles, the governor of the industrial Miranda state and a former presidential candidate, noted on social media his forces were ready to take control of Venezuela's unicameral parliament, according to The Associated Press.

"The results are as we expected. Venezuela won," Capriles said. "With great humility, serenity and maturity we accept what the people decided."

Maduro, meanwhile, blamed the result on an "economic war" waged by business leaders and other opponents out to sabotage Venezuela's economy and defeat his government.

"In Venezuela, a counter-revolution won, not the opposition," he said in a speech on Monday.

But the president vowed to accept the result, which marked the first time his socialist movement had lost an election in almost two decades.

"In Venezuela, peace and democracy must reign," Maduro said. "I've said we'll take the fight to the streets, but maybe I was wrong. We can't go where we've always been."

U.S. Secretary of State John Kerry, meanwhile, congratulated Venezuelans on Sunday's peaceful electoral process, the Department of State said in a statement.

"Venezuelan voters expressed their overwhelming desire for a change in the direction of their country," Kerry said.

"Dialogue among all parties in Venezuela is necessary to address the social and economic challenges facing the country, and the United States stands ready to support such a dialogue together with others in the international community."