Kremlin spokesman Dmitry Peskov told reporters Wednesday that U.S. sanctions against Russia for using chemical weapons in an effort to assassinate former spy Sergei Skripal would be “illegal.”

“We view these restrictions slapped by the U.S. against Russia as illegal and therefore we will treat similar steps in the same way if they follow,” said Peskov.

The prospective sanctions he referred to were announced by the U.S. State Department and House Foreign Affairs Committee on Tuesday. The State Department said Russian noncompliance with aspects of the Skripal investigation would trigger new sanctions under the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991.

House Foreign Affairs Committee Ed Royce (R-CA) was even more eager to place new sanctions on Russia, criticizing the Trump administration for not moving more quickly to do so after the Russians missed vital deadlines over the summer.

“It is unacceptable that the administration lacks a plan, or even a timeline, for action on the second round of mandatory sanctions required by U.S. law,” said Royce.

He referred to the Skripal poisoning in the U.K. as the latest in a “brazen” series of actions by Russia.

“The Trump administration needs to act quickly to uphold its own determination. Hesitation only encourages more Russian aggression,” Royce urged.

Administration officials said the August determination that Russia violated the 1991 chemical warfare law prompted some immediate sanctions and started a 90-day countdown to the second round of sanctions. Royce countered that he asked for a determination of Russian violations in March, received no response from the White House, and found it necessary to ask again in July.

“The administration is required to choose three from a group of six categories of sanctions under the law. The options include further restrictions on U.S. exports to Russia; restrictions on imports; a suspension of diplomatic relations with Moscow; a suspension of air travel to and from the United States by Russian government-owned air carriers; and sanctions preventing Russia from receiving multilateral development bank assistance or U.S. bank loans,” the Hill reported on Tuesday.

All of those options would take several weeks to implement, which means implementation will still be in progress when President Donald Trump meets with Russian President Vladimir Putin at the G-20 summit in Argentina at the end of November.