“The US [is] trying to form... alternative bodies of authority on vast... parts of the Syrian territory,” Lavrov said in a Friday news conference at the UN headquarters in New York.
“That is a fact and that does contradict their own obligations... to the territorial integrity and sovereignty of Syria,” he added.
On Wednesday, US Secretary of State Rex Tillerson said US troops would stay in Syria for the foreseeable future, adding that the US would not fund the reconstruction of any part of Syria, where President Bashar al-Assad is in power.
Tillerson elaborated on a US plan to push for a faster political transition in the country by discouraging economic relationships between Damascus and any other country.
Syria strongly condemned the US plan to maintain its military presence in the country as interference in its internal affairs and a blatant violation of international law.
According to figures the Pentagon released in December, there are at least 2,000 US troops in Syria as well as a diplomatic presence in cities such as Kobani.
'US confrontational strategy'
Lavrov also rejected US allegations that China and Russia were undermining efforts to enhance the international security, describing the strategy as "confrontational."
"It is regrettable that instead of having a normal dialogue, instead of using the basis of international law, the US is indeed striving to prove their leadership through such confrontational strategies and concepts," Lavrov said.
He made the remarks in reaction to the latest US national defense strategy released by Defense Secretary Jim Mattis on Friday which shifted focus from the country's so-called campaign against terror to "competition" with great powers.
Mattis claimed that Russia and China seek to "create a world consistent with their authoritarian models."
The Russian foreign minister described the strategy as the Pentagon's campaign for "additional financial resources."
Lavrov expressed Russia's preparedness "for dialogue" over military doctrines and expressed confidence that many US military officials understand the need for "strategic stability" which involves cooperation between Moscow and Washington.
Criticism of Russophobic intrigues
Elsewhere in his remarks, Lavrov urged Trump to counter "Russophobic" intrigues against the US president, in an attempt to improve relations between Washington and Moscow.
He argued that any improvement in Moscow-Washington relations is contingent upon "the preparedness and capability of Mr. Trump to counter the domestic intrigues which are directed first and foremost against him."
"Such intrigues are playing the Russophobic card," Lavrov said.
The senior Russian diplomat expressed confidence that Americans will eventually get tired of the anti-Russia rhetoric and recognize the fact that mending bilateral ties will be in their own interest.
"We see that all problems are blamed on Russia, and this domestic political life is using the Russophobic card for bad purposes," Lavrov said.
"But I am positive that the time of those who use such practices will pass," he added.
Since early 2017, American intelligence agencies have claimed that Russia interfered in the 2016 election to try to help Trump defeat Democratic nominee Hillary Clinton. They alleged at the time that Moscow’s interference included a campaign of hacking and releasing embarrassing emails, and disseminating propaganda via social media to discredit Clinton’s campaign.
Trump, for his part, has long denied any collusion between his campaign and Russian operatives during the White House race, which led to Clinton’s loss.
Russia has strongly rejected the claims about Moscow's interference in the US election in favor of Donald Trump, with Russian President Vladimir Putin calling the allegations as mere “fantasies.”