LONDON (AP) — Eddie Jones couldn't help himself. As the England rugby coach passed Joe Schmidt in a hallway, he warned the Ireland coach, "I'll find another couple of grenades to throw in."

He was only half-kidding at the posh Hurlingham Club during the Six Nations launch on Wednesday. The mind games started days ago when Jones stoked the buildup to their opening-round match next week in Dublin by claiming Ireland flyhalf Jonathan Sexton receives preferential treatment from the referees.

"There's a bit of shrapnel in the ether," Schmidt said with a smile.

Jones had only compliments on Wednesday for the Irish, but there's still 10 days to what Ireland captain Rory Best described as "a monster test match," a bold and sensational opening fixture featuring the teams who have shared the last five championships.

Schmidt was more taken aback by a Jones comment that "if you want to go to Ireland and win, you've got to deliver brutality."

He added: "We're pretty well primed. We need to be."

Schmidt expects the English to try to bully Ireland after a miserable Six Nations a year ago because they had the firepower, especially with the Vunipola brothers injury-free after missing the November series.

England captain Owen Farrell, recovering quickly from a minor thumb operation, said having Billy and Mako Vunipola has lifted their squad, already buoyant after a better-than-expected November, by providing excitement and inspiration.

Asked to elaborate on his 'brutality' remark, Jones said every Six Nations game was brutal. "I'm sure Ireland aren't over there in Portugal sun-baking," he said.

Ireland and England will be in Portugal at the same time this week for warm-weather camps, but the coaches aren't likely to meet until game day in Dublin. Jones said Schmidt has never invited him out, without adding if he's ever invited Schmidt.

But Jones had dinner with Wales coach Warren Gatland on Tuesday. Topics included the state of rugby in their countries and Gatland's native New Zealand, and how refereeing could improve.

"That took a couple of curries," Jones said with a smile.

"We're competitors but colleagues," he added. "Not unlike players having a beer together after a game."

Gatland said they understand as coaches what each other goes through, and it's important to share knowledge, to keep up to speed.

Wales has been up to speed for 10 months, since beating Italy last March began a run of nine successive wins, including a first ever four-from-four November. Wales needs to beat France and Italy on the road to match the 1910 team's Welsh record, then take out England at home to own it outright.

Gatland will be without star fullback Leigh Halfpenny for the first two matches, and is mainly concerned with keeping his stock of locks fit with Jake Ball and the uncapped Adam Beard back from injuries, and Cory Hill needing a shoulder injection last weekend. To captain and Wales' best lock, Alun Wyn Jones, beside him, Gatland quipped: "Don't get injured."

While the opening weekend is expected to reduce the title contenders to three, the championship should remain undecided until the last weekend when Wales hosts Ireland in Cardiff. Not only might a grand slam be on the line, but also a grand send-off for Gatland or Schmidt, both of whom are stepping down after the Rugby World Cup in Japan. Both are determined to go out in style.

But both have to go through Murrayfield, where Scotland is far tougher than outside it.

And both also have to go to Rome, where Italy gives its utmost, and promises to lay down for nobody with captain Sergio Parisse fit again.

Gatland hasn't won the Six Nations since 2013, but has the squad depth and confidence to win a fourth title.

"I remember at the last Five Nations (in 1999), the conversation was all about England and France and how they were the best two teams and were going to win and why don't they play the last weekend?" Gatland said. "What's brilliant now is that five teams can win. Italy is still a work in progress, like France were 80 years ago."

Jones said at his first Six Nations in 2016 he didn't agree with the tournament's tag as rugby's greatest championship, but believes it now.

"All teams are fitter and better organized," Jones said. "Five teams can win it, and Italy can cause an upset. It all makes it a little more challenging."