WASHINGTON — A senior Ukrainian lawmaker called Wednesday for the United States to impose secondary sanctions on China and India if they keep buying Russian energy, urging total solidarity against Moscow’s invasion.

On a visit to Washington, Oleksandr Merezhko, who heads the foreign affairs committee in Ukraine’s parliament, also called for greater ties with Taiwan, the self-governing democracy claimed by Beijing.

Merezhko said he has faced criticism at home that a tougher stance on oil purchases could push China to step up support to Russia, with Beijing for now stopping short of military assistance to Moscow.

“I’ve been trying to explain that this is not the problem. China is not afraid of Ukraine; China is afraid of American sanctions,” he told reporters of the State Department Correspondents’ Association.

“Which means the United States can and should deter China from helping Russia and preferably introduce secondary sanctions to stop China from financing the Russian economy and the Russian military machine by buying Russian oil and gas,” he said.

The ruling party lawmaker said he had lived in New Delhi and found the question of India’s oil purchases “painful” but he also backed sanctions against buyers from Russia in the world’s largest democracy.

“They should be consistent. This is a global conflict between democracy — the free world — and authoritarian regimes,” he said.

“There shouldn’t be any compromise because of material economic interest.”

China and India, the world’s sole nations with billion-plus populations, are both heavily dependent on imported energy and have historic ties with Russia.

The United States has employed secondary sanctions before, for years punishing foreign companies that buy any oil from Iran.

Merezhko was visiting Washington alongside his counterparts from Poland and Lithuania as they push lawmakers and others to support Ukraine.

The United States has imposed sweeping sanctions on Russia and approved billions of dollars in weapons for Ukraine, although several lawmakers in the new Republican majority in the House of Representatives have called for reductions in spending.

The head of the Lithuanian parliament’s foreign affairs committee, Zygimantas Pavilionis, warned that letting up pressure on Russia would have serious consequences.

“Vilnius will be Bucha in six, seven years if we do nothing,” he said, referring to Lithuania’s capital and the town near Kyiv where Ukrainians in civilian clothes were found shot dead with their hands tied behind their backs as Russia retreated.

Tiny Lithuania has been at the forefront of relations with Taiwan, angering China by letting Taipei open an office.

“China is the only country on this planet that can change the rules of the game completely — change it all, turn this world into a concentration camp,” he said.

“If Americans are ruled by fear and they do not defend Ukraine, the next morning we will all wake up with some events in the Taiwan Strait and the Indo-Pacific will be under attack,” he said.