India slammed the U.K.’s decision to exclude vaccinated Indian travelers from its new travel guidelines, calling it “discriminatory” and warning of reciprocal measures.

The British government will next month allow fully vaccinated travelers from a list of countries to skip quarantine upon arrival — but Indians who are fully vaccinated will still need to be quarantined.

The U.K. last week eased travel restrictions for fully vaccinated individuals from 17 countries and territories, including Japan and Singapore, saying they would not have to stay in quarantine for 10 days after arriving in England.

From Oct. 4, travelers from those destinations would have to show that they received a full course of one of the Covid vaccines currently approved in the U.K., at least two weeks prior to their arrival. The approved vaccines are: Oxford/AstraZeneca, Pfizer-BioNTech, Moderna or Janssen.

India’s main vaccine is the one from Oxford University and British-Swedish pharma giant AstraZeneca — but it is manufactured locally by the Serum Institute of India under the name Covishield. It has been approved for emergency use by the World Health Organization.

“The basic issue is that here is a vaccine, Covishield, which is a licensed product of a U.K. company, manufactured in India,” India’s Foreign Secretary Harsh V Shringla said Tuesday at a press briefing. “We have supplied 5 million doses to the U.K., at the request of the government of the U.K. We understand that this has been used in their national health system.”

“Therefore, non-recognition of Covishield is a discriminatory policy and does impact on those of our citizens traveling to the U.K.,” he added.

Under the new rules, Indian travelers will be required to quarantine after arriving in England and must undergo three rounds of testing, regardless of their vaccination status. Many Indian nationals typically travel to the U.K. for work, study, leisure travel or to visit family.

India’s External Affairs Minister Subrahmanyam Jaishankar, who is in New York for the United Nations General Assembly, raised the issue “strongly” with U.K. Foreign Secretary Elizabeth Truss, according to Shringla.

“I am told that certain assurances have been given that this issue would be resolved,” he said.

Jaishankar tweeted that during his meeting with Truss in New York, he “urged early resolution of quarantine issue in mutual interest.”

Indian opposition lawmaker Shashi Tharoor said he pulled out of a debate engagement at the University of Cambridge due to the quarantine order.

“It is offensive to ask fully vaccinated Indians to quarantine, he said.

Another lawmaker, Jairam Ramesh, said the decision “smacks of racism.”

“We will have to see how it goes, but if we don’t get satisfaction, we would be within our rights to impose reciprocal measures,” Shringla added, without elaborating what some of those measures could be.

Government data showed India has so far administered more than 825 million vaccine doses in one of the world’s largest inoculation drives — roughly 15% of the country’s eligible population has received the two doses required to be considered fully vaccinated, according to online publication Our World In Data.

The country’s home-made vaccine from Bharat Biotech, called Covaxin, has yet to be approved by the World Health Organization. It will likely to further complicate international travel plans for many Indian nationals.