WASHINGTON — The Trump administration said Wednesday it would impose extensive new sanctions against Russia, banning a wide range of exports and other measures, as punishment for its use of a nerve agent in an attempt in March to assassinate British citizen and ex-Russian intelligence officer Sergei Skripal and his daughter.

The sanctions again highlighted the gap between President Donald Trump's conciliatory language toward Russia and the tough position taken by many in Congress and within the administration.

Trump, who has resisted congressional insistence on additional sanctions on Russia for election interference and other activities, appeared to have had little choice in the matter, however. Under a 1991 law, he was required to act once the administration determined Russian responsibility for a chemical or biological weapons attack.

A release from the State Department said that such determination had now been made by Secretary of State Mike Pompeo over the attack this spring in Salisbury, England - following a British government conclusion that the administration had said months ago it accepted.

Russia, which was informed of the measures Wednesday, has denied responsibility for the attack.

A State Department official said the first new sanctions would take effect in two weeks, including a broad ban on technology exports to Russia. Most national-security-related technology is already restricted, but some is permitted on a case-by-case basis. When the new ban is in place, the official said, nearly all export requests - including electronics and engines - will be denied. The official briefed reporters under a State Department-imposed condition of anonymity.

Unless Russia agrees within 90 days to stop all use of chemical weapons and permit inspections to confirm their elimination, the law requires selection from a broad range of additional measures, including withdrawal of U.S. support for international loans and U.S. bank loans, prohibition of landing rights for Russian airlines, and suspension of diplomatic relations.

The export bans will apply to all state-owned or state-funded enterprises in Russia, a category the State Department official said could encompass 70 percent of the Russian economy and 40 percent of the workforce.

Once fully implemented, the sanctions could cut off hundreds of millions of dollars in exports, the official said. Two-way trade between Russia and the United States totaled $38 billion in 2013, the last year for which figures are posted, according to the Office of the U.S. Trade Representative. Since then, the amount is believed to have decreased, with Russia continuing to hold a surplus. U.S. exports are primarily machinery and technical goods, while leading U.S. imports from Russia are petroleum products.

Some U.S. technology exports will likely get waivers allowed by the law, the official said, including equipment needed for the International Space Station and parts for commercial airliners to ensure they can fly safely.

The 1991 Chemical and Biological Weapons Control and Warfare Elimination Act "requires the President to make a determination with respect to whether a country has used chemical or biological weapons in violation of international law or has used lethal chemical or biological weapons against its own nationals." Once that determination is made, sanctions are mandated, unless the president determines it is in the national-security interest of the United States to waive them.

The State Department official said there was no contradiction between Trump's efforts to improve relations with Russia and the penalty required by Congress.

"This is a question not of Russia policy per se, but of implementing laws that Congress has put in place," the official said. "This is not about different bits of the administration going in different directions. We are all one administration, and we're all on the same page here . . . We are tough on Russia, and at the same time we're quite committed to working to maintain relations because there are important things at stake here. We work on cooperative things where it is possible to do so, and we cry foul when it's necessary to do so."

In March, two weeks after the attack on the Skripals, Trump signed a statement, together with the leaders of France, Germany and Britain, blaming Russia for the assassination attempt on the former Russian military officer, who was convicted of spying for Britain. Skripal settled in Britain after a 2010 prisoner exchange.

The statement demanded that Russia "address all questions" related to the attack and provide "full and complete disclosure" of its program to produce the nerve agent, called Novichok.

Trump also ordered the expulsion of 60 Russians, including 12 identified as intelligence officers, and closed the Russian consulate in Seattle. The move was part of a wave of similar actions taken by Western countries in solidarity with Britain.

Last month, British Prime Minister Theresa May urged Trump to raise the issue of the poisonings when he met with Russian President Vladimir Putin in Helsinki, although it remained unclear whether the subject came up in their talks.

The Organization for the Prohibition of Chemical Weapons, the international chemical weapons watchdog, concluded in April that the nerve agent Novichok, known to have been first produced by the Soviet military, had been used in the attack against the Skripals, both of whom survived, although it did not assign blame.

In June, two British citizens living near Salisbury, where the Skripals were poisoned, also came in contact with Novichok. One of them, Charlie Rowley, said that he believed the poison came from a bottle of what he thought to be perfume that he found on the ground and gave to his girlfriend, Dawn Sturgess. Both quickly sickened with what the British government said was Novichok, although it had not yet determined whether the poison was the same batch as that administered to the Skripals.

Sturgess, 44, died a week after the exposure.

The State Department official said Pompeo's delay in making a determination on a violation of the 1991 law was because the issue is "intrinsically complicated."

The administration acted on the same mandate in 2017, imposing new sanctions on North Korea after a chemical attack in the international airport in Kuala Lumpur, Malaysia, killed the estranged half brother of North Korean leader Kim Jong Un.