WASHINGTON (Reuters) – Senior Democratic and Republican U.S. lawmakers want Washington to respond to Russia’s alleged interference in the U.S. election and actions in Ukraine and Syria, despite Republican President-elect Donald Trump’s calls to improve relations.

Senator Ben Cardin said on Wednesday he was working on what he described as “comprehensive” legislation to respond to Russian actions contrary to U.S. interests in Europe and Syria, as well as cyber attacks blamed on Moscow during the campaign.

“Russia presents a very serious challenge for America. They’re not our partner. They’re a bully,” Cardin, the top Democrat on the Senate Foreign Relations Committee, told reporters.

“Whether you attack us by MiG (fighter jet) or by mouse, it’s an attack. It requires a response. It’s clear that they were responsible for the cyber attack on our country in this past election,” Cardin said.

Other lawmakers have also called for action against Russia as they returned to Washington this week for the first time since Trump won the Nov. 8 U.S. election.

On Tuesday, Republican Senator Lindsey Graham, one of his party’s senior foreign policy voices, told reporters he wanted Senate hearings on whether Russian President Vladimir Putin interfered in the election.

“We can’t sit on the sidelines,” Graham said.

During the campaign, Trump’s Democratic rival, former Secretary of State Hillary Clinton, criticized him for praising Putin as a strong leader and saying ties with Russia should be improved at a time when Moscow and Washington are at odds over Syria and Ukraine.

Trump also worried U.S. allies with comments questioning NATO’s mutual self-defense pledge and suggesting he might recognize Russia’s 2014 annexation of Ukraine’s Crimea region.

Cardin declined to provide specifics about his legislation ahead of a planned speech on Thursday on Russia policy. When asked if it would include additional sanctions, he said, “It will be comprehensive.”

He said he thought it would be difficult to pass a bill before the current Congress wraps up next month, but that he hoped to lay the groundwork for future action.

Cardin also said he wanted Obama to act before he leaves office on Jan. 20. Congress has already passed legislation giving the president the authority to take actions including imposing additional sanctions or sending more arms to Ukraine.

(Additional reporting by Richrd Cowan; Editing by James Dalgleish)

IMAGE: U.S. Republican presidential candidate Graham speaks at the the Iowa Faith and Freedom Coalition Forum in Des Moine. Reuters.