WASHINGTON, March 13, /ITAR-TASS/. Possible US and other Western countries’ sanctions against Russia over the situation in Ukraine would negatively affect the process of settling a number of key international problems, US Secretary of State John Kerry said.

Speaking in opening remarks before the House Appropriations Subcommittee on State, Foreign Operations, and Related Programs, Kerry said Wednesday he meant in particular the Syrian conflict, the Iranian nuclear problem and developments in Afghanistan.

“We don’t think anybody is more served, better served, not for the interests of our efforts in Iran, not for the interests of our efforts in Syria, not for the interests of our efforts with nuclear weapons or Afghanistan or many other places, by isolating Russia,” the top US diplomat said.

“But we will do what we have to do if Russia cannot find the way to make the right choices here. And our job is to try to present them with a series of options that are appropriate in order to try to respect the people of Ukraine, international law, and the interests of all concerned,” he said.

Ukrainian President Viktor Yanukovich left Ukraine in February after a coup in his country. He told reporters in southern Russia on Tuesday that he remained the legitimate Ukrainian leader despite “an anti-constitutional seizure of power by armed radicals.” Russia also considers Yanukovich the legitimate Ukrainian president.

A number of media earlier claimed Russian armed forces blocked some military facilities in Crimea. But top Russian officials, including President Vladimir Putin, have denied any unlawful activities by Russian armed forces in the Ukrainian autonomy that will on March 16 hold a referendum on whether to secede and join Russia.

Russia has said the decision of the Crimean parliament to hold the plebiscite is legitimate but the self-proclaimed new Ukrainian authorities and the West have cried foul over the upcoming referendum claiming it would be “illegitimate.”

Kerry also said Wednesday that US President Barack Obama instructed him to fly to London on Thursday for a later meeting with Russian Foreign Minister Sergey Lavrov dedicated to the settlement of the Ukrainian crisis.

“Our interest is in protecting the sovereignty and the independence and the territorial integrity of Ukraine with our European partners and others. We also have to be willing to try to sit down and de-escalate the situation,” he said.

“We will offer certain choices to Foreign Minister Lavrov and to President Putin through him, and to Russia, with hopes… that we will be able to find a way forward that defuses this and finds a way to respect the integrity and sovereignty of the state of Ukraine,” Kerry said without elaborating.

Kerry said his country “respects, obviously, that Russia has deep historical, cultural, and other kinds of interests with respect to Ukraine and particularly Crimea.”

In the Soviet Union, Crimea used to be part of Russia until 1954, when Nikita Khrushchev, the first secretary of the USSR’s Communist Party, transferred it to Ukraine's jurisdiction. In 1991, with the collapse of the Soviet Union, Crimea became part of newly independent Ukraine.

Crimea had the name of the Republic of Crimea in 1992, when it had its own Constitution and broader autonomy.