The new US administration of Donald Trump understands the need for caution in dealing with Russia, Foreign Secretary Boris Johnson has said.
After his first meeting with US secretary of state Rex Tillerson during the G20 summit in Bonn, Mr Johnson said they had agreed that dealings with the Kremlin had to be handled in a "very guarded way".
While neither the US nor the UK wanted to see a return to the days of the Cold War, he said they were clear Moscow should not be allowed to carry on with its current behaviour unchallenged.
"I think Rex Tillerson is absolutely clear in his view, which is the same as mine. You have got to engage with Russia but you have got to engage in a very guarded way. You have got to beware of what they are up to," he told the BBC.
"There is no question that, when you look at Russian activity on the cyber front, when you look at what they are doing in the western Balkans, when you at what has been happening in the Ukraine, you have got to be very, very cautious.
"I think it is entirely right to have a dual-track approach.
"We don't want to get into a new Cold War. That's something London and Washington are completely at one on. But nor do we want Russian behaviour to continue as it is. Rex Tillerson has been very clear about that."
His comments come amid intense scrutiny in the US of the administration's attitude towards Russia following the resignation of national security adviser Michael Flynn over his contacts with the Russian ambassador to US before Mr Trump's inauguration last month.
Meanwhile, US defence secretary General James Mattis, attending a meeting of Nato defence ministers in Brussels, brushed aside an offer by Vladimir Putin of co-operation with Western intelligence agencies to combat international terrorism.
The Russian president said it was in the interests of both Russia and the West to work together in the counter-terrorism arena.
"It's in the general interest to establish a dialogue with the special services of the United States and other member countries of Nato," he said at a meeting of top officials of the Federal Security Service.
"We need to establish co-operation at a new level in the anti-terrorist sphere with foreign partners."
Gen Mattis, however, said the Kremlin had to show it was prepared to abide by international law and honour past agreements with Nato if there was to be any return to security co-operation which was broken off by the US following Moscow's annexation of Crimea in 2014.
He said there was currently "very little doubt" that Russia had either interfered or tried to interfere in a number of elections in the democracies.
"We will engage politically. We are not in a position right now to collaborate on a military level but our political leaders will engage and try to find common ground or a way forward where Russia, living up to its commitment, will return to a partnership of sorts here with Nato," he said.
"But Russia is going to have to prove itself first and live up to the commitments they have made."