LONDON (BLOOMBERG) - British Prime Minister Boris Johnson said England is on course to be able to lift coronavirus restrictions as planned on July 19, despite the spread of the delta variant.

But Johnson also warned that foreign travel is likely to continue to be be disrupted this year, with delays and complications for travellers.

Officials will be studying pandemic data and vaccination rates in Britain and overseas as they weigh up lifting restrictions in the days and weeks ahead, he said.

The spread of the delta variant has already forced the government to delay the fourth and final stage of its plan to ease pandemic rules in England, which was due to take effect on June 21. Johnson pushed the date back by a month to July 19.

Speaking to a television crew, Johnson said "looking at where we are" and the effectiveness of vaccines against all the known variants, "I think it's looking good for July 19 to be that terminus point".

He confirmed ministers will be looking at whether to ease the requirement for travellers to quarantine on return to England if they've been fully vaccinated.

"We will certainly be looking at that but I want to stress that this is going to be, whatever happens, a difficult year for travel," Johnson said.

"There will be hassles, there will be delays, I'm afraid, because the priority has got to be keeping the country safe and to stop the virus coming back in."