MOSCOW/WASHINGTON (Reuters) - Angered by expanded U.S. sanctions, Russia on Wednesday canceled a high-level meeting between Russian Deputy Foreign Minister Sergei Ryabkov and U.S. Undersecretary of State Thomas Shannon.

Russian Deputy Foreign Minister Sergei Ryabkov looks on at the start of two days of closed-door nuclear talks at the United Nations offices in Geneva October 15, 2013. Iran will face pressure on Tuesday to propose scaling back its nuclear programme to win relief from crippling sanctions as talks between world powers and Tehran resume after a six-month hiatus. REUTERS/Fabrice Coffrini/Pool

The move cast some uncertainty over plans for the first face-to-face meeting between U.S. President Donald Trump and Russian President Vladimir Putin on the sidelines of the upcoming G20 summit on July 7-8 in Hamburg, Germany.

With two weeks to go, a senior White House official said no plans for a bilateral meeting had been finalized. “Nothing has been canceled because nothing has been set,” the official said.

Moscow said it was obliged to cancel the diplomatic meeting after the U.S. government on Tuesday added 38 individuals and organizations to its list of those sanctioned over Russian activities in Ukraine.

The new U.S. sanctions were “a continuation of the trend set by the Obama administration aimed at ruining relations between our countries”, Ryabkov said in a statement posted on the website of Russia’s Foreign Ministry.

U.S.-Russian relations have already been strained by allegations that Moscow interfered in the U.S. presidential election last year and Trump’s first five months in office have been dogged by a controversy over whether his campaign team colluded with Russia.

Trump has said he wants to explore whether Washington and Moscow can work together on issues of mutual concern, such as fighting Islamic State insurgents in Syria.

But tensions between the two nations have escalated. On Sunday, the U.S. military shot down a Syrian military jet. That prompted Russia to change its military posture.

The Kremlin said the expanded U.S. sanctions undermined Washington’s assertions it wanted dialogue with Moscow, calling the new sanctions a “political gift” to Ukrainian President Petro Poroshenko, who visited Trump at the White House on Tuesday.

The U.S. State Department said it regretted the Russian cancellation, but remained open to future discussions to try to bridge bilateral differences.

The new sanctions only reinforced existing sanctions, which have been updated twice a year since they were first imposed, the department said.

“Let’s remember that these sanctions didn’t just come out of nowhere. Our targeted sanctions were imposed in response to Russia’s ongoing violation of the sovereignty and territorial integrity of its neighbor, Ukraine,” State Department spokeswoman Heather Nauert said in a statement.

The Kremlin said earlier on Wednesday that Russian forces were not present in eastern Ukraine, which is controlled by pro-Russian separatists.

The United States and the European Union have imposed several rounds of sanctions on Russian companies and individuals in response to Russia’s role in the Ukraine conflict.

Lawmakers in the U.S. Senate last week also backed additional sanctions to punish Russia for alleged meddling in the 2016 U.S. election, its annexation of Ukraine’s Crimea region, and support for Syria’s government in the six-year-long civil war.

Ryabkov was meant to be meeting Shannon in St Petersburg on Friday to discuss “problems in bilateral ties”.

But Ryabkov, in the same statement on Wednesday, accused the United States of failing to propose anything tangible to improve relations.

He said: “Previous multiple waves of American sanctions haven’t achieved the result which their initiators had hoped for. Any new attempts to make Russia ‘bow down’ will be just as futile.”