The government said a short delay "would give negotiators the flexibility to make progress".
The move would assuage British defence industry concerns that Brexit will lead to greater Franco-German cooperation, gradually pushing the United Kingdom out of major defence markets. "It's not the be all and end all".
Verhofstadt, a former Belgian prime minister, told a news conference in Strasbourg, France, where the parliament is meeting: "For the moment we don't see sufficient progress, clearly".
The government emphasised that "NATO will continue to be the cornerstone" of its security upon leaving the EU in March 2019 but that Britain would seek a UK-EU relationship that is "deeper than any third country partnership".
Chancellor of the Exchequer Philip Hammond will try to reassure the European Union that Britain isn't going to use Brexit to undercut financial regulations, as Theresa May's government adopts a more conciliatory tone in its negotiations.
"After we leave the European Union we will continue to face shared threats to our security, our shared values and our way of life", Brexit minister David Davis said.
While Juncker can expect a generally warm reception in the European Parliament, a broadly federalist body with the noisy exception of dedicated anti-EU parties, the test of whether his proposals translate into action will be the reactions in the coming months of national leaders in the 27 member states.
FILE PHOTO - EU and British flags fly outside the European Commission building in London, Britain August 12, 2017.
Meanwhile, Italy has handled an influx of migrants and refugees.
"When I stood before you this time previous year, I had a somewhat easier speech to give".
Its economic growth has outpaced that of the United States for the past two years and unemployment, while still far too high in many European countries, particularly among young people, is at a nine-year low overall. "Europe was battered and bruised by something that shocked our very foundation", Juncker said in his opening remarks.
"We want to fight terrorism together". Mr Junker noted the wrapping up of a trade deal with Canada during the past year, and negotiations on deals with Japan, Australia and New Zealand.
After fierce criticism from Britain over inefficiency in the EU, Juncker proposed that his role as president of the European Commission be merged with that of the European Council.
He will call for countries that are outside the eurozone and the Schengen passport-free area to join, they added.