President Trump's team has missed a deadline for implementing new sanctions against Russia, and has ignored congressional requests for more information, according to a pair of leading senators.

"They've had plenty of time to get their act together," Senate Armed Services Chairman John McCain, R-Ariz., and Maryland Sen. Ben Cardin, the top Democrat on the Foreign Relations Committee, said Wednesday.

McCain and Cardin spearheaded a congressional effort to impose far-reaching sanctions on Russia in response to President Vladimir Putin's aggression in a variety of arenas. The bill passed with near-unanimity in the Senate, and Trump opposed the bill but signed it. But the Trump team missed an October 1 deadline for implementing the sanctions, which target Russia's defense and intelligence sectors.

"The delay calls into question the Trump administration's commitment to the sanctions bill which was signed into law more than two months ago, following months of public debate and negotiations in Congress," the senators said.

"We wrote the Administration on September 28, strongly urging them to develop a robust and comprehensive implementation plan for all aspects of the law and to work in close consultation with Congress to ensure a fulsome reflection of congressional intent," McCain and Cardin said. "We again request that the administration respond to our letter, and engage Congress in a serious way moving forward."

Trump's opposition to the sanctions was controversial throughout the congressional debate, and some lawmakers regarded it as a sign of his unwillingness to punish Russia for the 2016 disinformation campaign and cyber-attacks against Democrats. But Trump's team maintained that they needed flexibility to increase or lower diplomatic pressure on Russia.

"Essentially, we would ask for the flexibility to turn the heat up when we need to, but also to ensure that we have the ability to maintain a constructive dialogue," Secretary of State Rex Tillerson told House lawmakers during a June hearing.

Congress ignored that request and passed new sanctions. Putin retaliated by ordering the State Department to slash hundreds of U.S. personnel in the country. Trump's administration complied, but announced that three Russian facilities in the United States would be closed simultaneously.

The October 1 deadline to implement new Russia sanctions coincided with the deadline that the State Department gave for families of Russian diplomats to vacate the facilities that Tillerson had ordered closed in September.