MOSCOW (REUTERS, AFP) - The Kremlin said on Friday it fully agreed with US President Donald Trump who said in a Twitter message that Washington's "relationship with Russia is at an all-time and very dangerous low".

Trump's comments posted on Thursday came one day after he grudgingly signed new sanctions against Russia into law, a move Moscow said amounted to a full-scale trade war and an end to hopes for better ties with the Trump administration.

"We fully share this opinion," Kremlin spokesman Dmitry Peskov told a conference call with reporters when asked about Trump's Twitter message.

"The danger may lie in a deficit of interaction and cooperation in those matters which are vitally important for our two countries and peoples."

Trump, writing after he reluctantly signed a bill approved by Congress for strengthening sanctions against Russia, tweeted: "Our relationship with Russia is at an all-time & very dangerous low.

"You can thank Congress, the same people that can't even give us HCare!", Trump said, referring to the Republican-dominated legislature's failure to implement a campaign pledge to change the US healthcare system.

Moscow has reacted furiously to the sanctions. Russian Prime Minister Dmitry Medvedev On Wednesday said they amounted to a "full-fledged economic war" and demonstrated Trump's "total weakness by handing over executive power to Congress in the most humiliating way."

The Kremlin spokesman on Friday also slammed the ongoing investigation into Trump's alleged collusion with Russia during the election campaign, calling this "Russiagate," a reference to the Watergate scandal that led to the resignation of Richard Nixon.

"We have many times talked about the complete absurdity and lack of basis for so-called Russiagate," Peskov said.

Russian Foreign Minister Sergei Lavrov is set to meet US Secretary of State Rex Tillerson in Manila at the weekend to discuss bilateral ties, the Russian foreign ministry confirmed Thursday after the diplomatic chiefs spoke by phone.