Vladimir Putin says trust has eroded between the US and Russia under President Donald Trump, as Moscow delivers an unusually hostile reception to Secretary of State Rex Tillerson in a face-off over Syria.
Any hope in Russia the Trump administration would herald less confrontational relations has been dashed in the past week after the new US leader fired missiles at Syria to punish Moscow's ally for its suspected use of poison gas.
Mr Tillerson started a meeting with Putin in the Kremlin on Wednesday after talking to his Russian opposite number Sergei Lavrov for around three hours. The Kremlin had previously declined to confirm Mr Putin would meet Mr Tillerson.
"One could say that the level of trust on a working level, especially on the military level, has not improved but has rather deteriorated," Mr Putin said in an interview.
In his interview, Mr Putin doubled down on Russia's support for Syrian President Bashar al-Assad, repeating denials that Mr Assad's government was to blame for the gas attack last week and adding a new theory that the attack may have been faked by Mr Assad's enemies.
Mr Tillerson's official itinerary in Moscow started with the meeting with Mr Lavrov, in an ornate hall in a foreign ministry-owned residence. In opening remarks in front of reporters, Lavrov greeted Mr Tillerson with unusually icy remarks, denouncing the missile strike on Syria as illegal and accusing Washington of behaving unpredictably.
Mr Lavrov also noted that many key State Department posts remain vacant since the new administration took office - a point of sensitivity in Washington.
One of Mr Lavrov's deputies was even more undiplomatic.
"In general, primitiveness and loutishness are very characteristic of the current rhetoric coming out of Washington," Deputy Foreign Minister Sergei Ryabkov told Russia's state-owned RIA news agency.
Mr Tillerson kept to more calibrated remarks, saying his aim was "to further clarify areas of sharp difference so that we can better understand why these differences exist and what the prospects for narrowing those differences may be".
Moscow's hostility to Trump administration figures is a sharp change from last year, when Mr Putin hailed Mr Trump as a strong figure.
The White House has accused Moscow of trying to cover up Mr Assad's use of chemical weapons after the attack on a town killed 87 people last week.
Separately on Wednesday, the US said there are credible reports that Russia attempted to interfere in elections last October in Montenegro, which formally became a member of NATO this week.
US Ambassador to the United Nations Nikki Haley told Russia it was isolating itself by supporting Mr Assad and that it was "long past time for Russia to stop covering for Assad".